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One K Defender Matte Helmet

One K
- Item #21807

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We're bringing you this product at the lowest price allowed by the manufacturer so you won't find it cheaper anywhere else. This also means we can't apply any further discounts or promotions.

As riders and online shoppers, we know it can be tough to buy a new bridle or pair of boots without trying them on. That's why we moved the fitting room to your living room (or barn)! From breeches to blankets, if you or your horse can try it on, you can return it, free! Just use the pre-paid return label included in your order within 60 days from the purchase date. And of course, please make sure the item is in like-new condition with original packaging (we said 'fitting room', not 'war room'!).

Why We Love This

The One K Defender Matte Helmet is sure to keep you cool with two side, two front, one back, and two center stripe vents! This all-around stylish helmet is great for both schooling and showing in a number of different disciplines!

Favorite Features

  • Polycarbonate and Advanced ABS Composite outer shell with an injection molded shell design
  • Inner lining is anti-microbial, moisture wicking, quick drying, and washable
  • Stainless steel mesh
  • Comfort padded harness with synthetic suede lining and Fastex buckle
  • ASTM/SEI F1163-15 certified


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    out of 5
    94% of customers would recommend this product to a friend!
    Tell us what you think!

    SmartPak customers are some of the most conscientious animal owners around. We encourage you to share your experience with the products we sell to help fellow customers to make informed choices for their animals. We do not edit these reviews in any way - they are direct customer-to-customer communication. We do monitor reviews for positive and negative feedback, and use this feedback to improve our selection as well as sharing feedback with product manufacturers to help them improve their products. Please note that we recommend consulting your vet with serious health issues.

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    One K Defender Matte Helmet is rated 4.619 out of 5 by 63.
    Rated 5 out of 5 by from Great fit and very light Great fit and very light with good airflow. Washable as well
    Date published: 2015-11-19
    Rated 5 out of 5 by from Nice helmet Nice helmet. I haven't owned it long enough to rate durability, but the easily removable and snap back in liner is something I appreciate. Replacement liners are available, too. Harness is comfortable and snaps nicely. My regular IRH was on months' of backorder and I read reviews saying this is what riders had switched to because of similar fit. I agree. Note that my measured size was right on the cut off between two helmet sizes. If you are in doubt, order up a size. Smartpak easily exchanged my too small helmet for the correct size.
    Date published: 2015-11-17
    Rated 5 out of 5 by from Beautiful helmet! I brought this a month ago and I love it! It's beautiful! The first thing I noticed was the airflow and ventation. I got many compliments from how nice it looked; someone even thought it was a samshield. I love how easy it is to take out the inner cushion. It makes washing it easier and allows me to avoid the terrible helmet smell I have gotten in my past helmets. It's my schooling and showing helmet(it's that nice).
    Date published: 2015-11-03
    Rated 4 out of 5 by from Great Price & Looks Great in the show ring! I bought this helmet after loving my matte Samshield! This helmet takes a little while to break in, it is pretty snug during the first few uses, but it looks great in the show ring and is priced well! I do feel that this helmet gives you a lot more airflow than the samsheild and still provides a removable liner for easy washing.
    Date published: 2015-11-02
    Rated 5 out of 5 by from Great Helmet! I bought this helmet for my daughter about a month ago. She loves it. It is much cooler than her previous helmet which is really important since we live in Florida. Looks great in the show ring!
    Date published: 2015-10-23
    Rated 5 out of 5 by from Daughters love it I bought this helmet for my daughters, they love the helmet. It was a bit snug the first time they tried it on, but it fits great now.
    Date published: 2015-10-08
    Rated 5 out of 5 by from Amazing helmet I got this helmet a few weeks ago and am so glad I did. It actually fits well and I'm I'm love with the matte finish. I can just clean it off with water, its great. It's also really comfortable.
    Date published: 2015-10-02
    Rated 5 out of 5 by from Excellent Helmet My one k is by far the comfiest and most breathable helmet I've ridden in. I love the look of a matte helmet and these are much cheaper than samshields. The interchangeable liners are lifesavers, especially for people with thick hair. The chin strap was a little tighter than I expected, but it's easily adjustable. And now I find myself preferring a tight chin strap because the looser chin straps feel unsupportive and uncomfortable
    Date published: 2015-09-24
    Rated 5 out of 5 by from I've ridden it is several times so far. It fits well and is comfortable. The price was very good for the quality. It shipped very fast and I was able to ride with it the next week. The Velcro piece on the chin piece hides the excess after adjusting the chinstrap length.
    Date published: 2015-09-22
    Rated 1 out of 5 by from Have not received yet. I would love to actual rate this helmet. I ordered them for my daughters Aug. 1 they were on back order. Didn't receive till Aug. 27. Had to return because they were too small. Did get free shipping on the return. Returned them Sept. 1 it is Sept 15 and I am still waiting for the replacement.
    Date published: 2015-09-15
    Rated 5 out of 5 by from Super comfy! Helmet looks a little large compared to my Charles Owen but it's super comfy! The ventilation is also great!
    Date published: 2015-09-15
    Rated 5 out of 5 by from Looks Great!!! I Love the helmet bought it for my daughter and she looks great and she says it does not make her head sweat alot . I am thinking pf getting one for myself.
    Date published: 2015-09-15
    Rated 5 out of 5 by from Same as a samsheild but less $$$ If you like the fit and the style of a samsheild but don't want to fork out all that cash this OneK is what you need. I love the fit and I like the matte finish. I also own a CO AYR8 which I enjoy to for a more classic look.
    Date published: 2015-09-15
    Rated 5 out of 5 by from Great helmet! It's very light weight and feels much cooler then my previous CO helmet.
    Date published: 2015-08-29
    Rated 4 out of 5 by from Nice helmet, some fitting issues I was extremely pleased to find a helmet with many of the same features as more expensive brands I had looked at. The quality is nicer than I expected and I was very pleased with the look of the helmet. Fit of this helmet is a little off for me- I usually wear a 7 1/4 in a Charles Owen with a hairnet, so I ordered the large. The fit is definitely tight, but I had read reviews saying the interior padding will squish down some, allowing extra room so I decided to keep it fearing the extra large might be too big. I have ridden in the helmet quite a few times and it's still a tight fit so I would recommend sizing up if you are in between sizes. I did experience some gaping at the temple areas with my CO which I don't have a problem with in this helmet, it fits my head shape nicely. Overall, I'm glad to have a well ventilated schooling helmet for the hot climate I live in.
    Date published: 2015-08-26
    Rated 5 out of 5 by from LIKE WEARING A CLOUD ON YOUR HEAD! I absolutely LOVE this helmet. I have never worn a more comfortable helmet in my life, and I love the look! I recommend it to anyone :-)
    Date published: 2015-08-25
    Rated 5 out of 5 by from LOVE this helmet I own almost every brand of helmet out there and I love this one. I sweat A LOT and I could feel a slight breeze with this one and my head wasn't nearly so dripping. The removable liner is amazing. It's so light and doesn't make your head look huge. The finish is wonderful. It's so easy to clean and doesn't trap dirt like the suede and other finishes. I can't say enough good about this helmet.
    Date published: 2015-08-25
    Rated 2 out of 5 by from Weird chin strap I bought this on Helmet Awareness day. It didn't really fit correctly and I didn't like the chin strap. It seems like a nice enough helmet.
    Date published: 2015-08-24
    Rated 5 out of 5 by from great quality for the price Can't say enough good about this helmet! Got it during the "Helmet Awareness Day" sale, so it was less than $200. For that amount of money, it is phenomenal, and I wouldn't hesitate to pay full price. It is lightweight, low-profile and super cushion-y inside. Also well-ventilated.
    Date published: 2015-08-24
    Rated 4 out of 5 by from attractive and lightweight I wear this to polo practice and it's very nice looking and lightweight. It is a little tight and gives me a headache after too long, I think I just need to break the padding in as the next size up would be too big. I like that the chin strap comes forward a little more and doesn't give you a double chin look like some helmets!
    Date published: 2015-08-24
    Rated 5 out of 5 by from Great Helmet Lightweight and has good ventilation, I can actually feel the air flow through the top of the helmet. The liner could be more padded, but the helmet is still comfortable when you're wearing it. The chin strap is a little more forward than most other helmets but when adjusted properly it is still secure and comfortable. The Velcro on the harness is nice in that it eliminates the look of extra straps dangling, giving a nice polished look. Liner is easy to remove and install, haven't tried washing it. Overall, this helmet has all the same features of the Samshield (and more ventilation) at half the cost. I use mine for schooling but I have seen them gaining some popularity in the hunter/jumper show rings. For reference, I wear a 6 7/8 in a CO JR8 and the size Medium fit, but just barely. It was uncomfortably snug to start but after wearing it several times the liner has compressed and it is now comfortable.
    Date published: 2015-08-12
    Rated 5 out of 5 by from Versatile Helmet at good price My old helmet was past the 5 year mark, and per manufacturer recommendations it needed replaced. I had purchased the same helmet that I had had for the last 5 years (IRH Elite), but unfortunately the manufacturer has changed the shape and it no longer fits me. I loved my old helmet and was quite disappointed! Fortunately, free returns with Smartpak!I tried this helmet as there are limited options in the larger helmet sized (and within my price range..), and I am happy I did! This helmet is well ventilated, great looking and the shape does fit my head. The stock helmet liner makes the helmet a bit too tight for me, but I verified with the manufacturer that I can get the next liner size up and that will give my head a bit more room. The chinstrap is a bit tighter than I was expecting, but honestly I think I have been keeping my chinstrap too loose!
    Date published: 2015-08-11
    Rated 5 out of 5 by from Excellent Product! I needed a new helmet, and after lengthy research of all products I decided on a One K Defender helmet. I heard others rave about the comfort in the helmet but did not believe how comfy a helmet could be until I tried mine on. The chin strap does fall in front but frankly it makes the helmet seem more secure. I got a wonderful buy through SmartPak's recent sale. I could not be happier.
    Date published: 2015-08-08
    Rated 5 out of 5 by from Cool and Comfortable I bought this helmet because I had heard the One K was light weight, comfortable and cool. It has proven to be all of these things. I can feel the air flow through the vents which helps keep my head cool on those hot summer days. It is a great price for a schooling helmet.
    Date published: 2015-06-06
    Rated 5 out of 5 by from Great helmet! I absolutely love this helmet and you can't beat the price. My Samshield never fit right but this one fits great. Usually wear a 6 7/8 and I have very long hair, the medium fits perfect.
    Date published: 2015-06-06
    Rated 4 out of 5 by from Nice helmet I really like the way this fits on the head, however, the chin strap is a little snug. I feel it on my chin which I am not used to. It has been a while since I used to ride, so I have not purchased apparel in a long time. I decided to keep it and just deal with the strap issue. I was a little disappointed that the chin strap does not have enough slack to fit appropriately given the price.
    Date published: 2015-06-02
    Rated 5 out of 5 by from Love this helmet! I decided to purchase this helmet after my old charles owen jr8 got too small. Originally I wanted to get another CO or a samshield, but that was until I tried on this helmet. It is by far the most comfortable helmet I've ever worn, has super ventilation that actually works, and is also super low profile even on smaller heads (no more egg head for me!!). The comfortable chin strap and removable liner are an added bonus as well. Could not be happier with this product and I don't think I'll be switching from one k anytime soon.
    Date published: 2015-05-05
    Rated 5 out of 5 by from Great helmet. Great price. I live in coastal South Carolina and it is HOT during the months of July, August & September. This is the first helmet I have had with good ventilation at a good price. It is also the most comfortable helmet I have had in years. I cut all of my hair off so had to get a smaller helmet. The One K Defender helmet has been fantastic. Really love it.
    Date published: 2015-04-28
    Rated 5 out of 5 by from Love! This helmet is comfortable, looks good, and is on the inexpensive side. It seems like an affordable version of a Samshield. I love the removable liner. I haven't been able to test it in the heat yet, but it feels nice and light while still being substantial enough to save my head. :D My favorite thing about it, though, is that it looks as nice as a $400 helmet for half the price!
    Date published: 2015-03-10
    Rated 5 out of 5 by from Great helmet at a great price! I needed a new helmet but I didn't want to pay $500 for one. I had tried on this helmet at a local tack shop and I loved it! I chose to buy my helmet through smartpak because they have wonderful customer service and a price that couldn't be beat! The helmet is a great fit though a little tight when my hair is up inside it. That's not a problem though because in due time I'm sure it will stretch just enough. I highly recommend this helmet for the rider on a budget!
    Date published: 2015-02-28
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    Mollie and Eden
    I started riding when I was 9 years old and quickly got swept up into the competitive hunter/jumper world. I showed my first pony, Chloe, in the Small Pony Hunter divisions were we competed at shows like Fairfield Hunt Club, Old Salem, HITS, and West...

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