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One K (#21807)

One K Defender Matte Helmet

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Overview

Why We Love This

One K™ Defender riding helmets boast the perfect synergy between advanced technology and aesthetically pleasing design. This helmet features a polycarbonate and advanced ABS composite outer shell that’s tough but lightweight with a modern matte finish. It’s offered in both an oval shape and a round shape so that you can find the perfect fit for your head. You’ll love that the liner is moisture wicking, quick drying, anti-microbial, and washable to keep you cool, dry, and comfortable. Plus, the harness is padded for comfort and lined with easy-to-care-for synthetic suede to keep you as comfortable as you are stylish. It even has a Fastex buckle that makes taking it quick and easy to take on and off. Additionally, you’ll have plenty of ventilation with two side, two front, one back, and two center stripe vents for a total of seven vents. Last but not least, this helmet is ASTM/SEI F1163-15 certified, so you can have peace of mind that your head is in good heads. With enough features to appeal to those seeking everything a horseback riding helmet could offer, wrapped in a stylish package that traditionalists can appreciate, One K™ has the best of both worlds.

Additional One K Helmet Liners also available!

Imported

CAUTION: Safety equipment must fit properly and be appropriately secured with manufacture approved parts only. Altering or adding to safety equipment voids warranty and can result in injury. As a safety precaution, inspect all products prior to each use.

For additional information on fit, watch our video on how to fit your helmet. Click Here!

  • Polycarbonate and advanced ABS composite outer shell is tough but lightweight
  • Offered in oval and round shapes for a great fit
  • Inner lining is anti-microbial, moisture wicking, quick drying, and washable
  • Comfort padded harness with synthetic suede lining and Fastex buckle is comfortable, easy to use, and stylish
  • ASTM/SEI F1163-15 certified
  • Lots of vents to keep you cool and dry
  • Stylish design looks great in the ring
Key Specifications
  • ASTM/SEI: Yes
  • Oval: Yes
  • Round : Yes
  • STILL HAVE QUESTIONS? SEE Q&A
  • 100% Happiness Guarantee
    100% Happiness Guarantee
    At SmartPak, your happiness is at the core of everything we do. We put our products to the test in our barns and on our horses, and back every order with our world-class customer service so that you can shop with confidence. As part of our Happiness Guarantee, we promise you:
    • Expert advice from riders
    • Free shipping every day
    • Free return shipping on sized items
    • Hassle-free returns up to 365 days after purchase
Ingredients
(Maintenance Dose = )
Ingredient Amount
Sizing
What Customers Say:
Sizing Chart for One K Defender Matte Helmet
Specifications
ASTM/SEI Yes
Oval Yes
Round Yes
Reviews
One K Defender Matte Helmet is rated 4.7 out of 5 by 191.
Rated 5 out of 5 by from Love the oval option, nice helmet! I had quite a bit of trial and error with other brands before I found the right helmet to fit me. I figured out that it was mostly because of the oval shape of my head, so decided to try the One K since they do have the oval option. I measure just a touch over 57cm, so at first tried the size Large Oval. This helmet was much too big for me, even with the strap snugged all the way up. I exchanged for the Medium Oval and it fits like a glove! Very nice helmet and I love SmartPaks exchange policy!
Date published: 2020-11-05
Rated 5 out of 5 by from Great fit! Very comfortable and perfect for schooling and showing.
Date published: 2020-10-05
Rated 5 out of 5 by from Perfect fit!! I love that they offer a helmet in long oval, the only helmet that fits and does not give me a headache!!
Date published: 2020-10-02
Rated 5 out of 5 by from Favorite helmet I've owned so far! Love this helmet. It's comfortable and much cooler than my Charles Owen. It's nice enough to wear to most shows.
Date published: 2020-09-22
Rated 5 out of 5 by from Best helmet! I catch myself wearing this helmet long after I've dismounted. It's like it's molded to my head. Lightweight, hugs my head. Can't say enough good things about this helmet. It was recommended to me and I'm so glad I bought!!
Date published: 2020-07-28
Rated 5 out of 5 by from Exactly what I’ve been looking for I’ve been looking for the right helmet for myself for years....this is it! The long oval fits me great. I get headaches when I wear helmets and this one does not cause me any issues. It doesn’t put pressure on my temples which is great. The helmet tends to sit higher on your head so it relieves compression from that area. Ventilation is also AMAZING. I rode in 85 degree weather and my head didn’t sweat! Love this helmet.
Date published: 2020-07-19
Rated 5 out of 5 by from Fits great! Love the oval option. Other helmets only offer a round fit which was uncomfortable. This one fits great!
Date published: 2020-06-02
Rated 5 out of 5 by from Perfect Fit! This helmet fits so well. I have a small head and a narrow face...the long oval fit perfectly.
Date published: 2020-05-09
Rated 5 out of 5 by from Nice helmet Only weird thing are the straps the way they fit. But the helmet is much more comfortable than a Charles Owen!!! lightweight and not hot at all.
Date published: 2020-04-06
Rated 5 out of 5 by from I have only had this for a month, but ˆ like it. t fits my head really well.
Date published: 2020-01-17
Rated 5 out of 5 by from Love it As others have commented, the position on the chin strap feels odd... but only the first time I wore it. I never think about it now. The helmet feels truly comfortable, it is really secure on my head without being too tight and I like that the lining is washable (my previous helmet got to the point were it was disgusting)
Date published: 2020-01-17
Rated 5 out of 5 by from Perfect for Round Heads I'm on my second One K, and I love this helmet! I have a round shaped head, and helmet like the Charles Owen often give me headaches on the sides of my head. This helmet fits exceptionally well, and the moment I first put it on it felt secure and like it would provide great protection in a fall. It's light enough with great ventilation for the Texas summers, and I really like that the liners are removable so you can wash them. Turns out I'm on my second one because I did fall off my 4 year old. It was a shame throwing out the first one because it still looked beautiful, but I'm thankful to have had such a well designed helmet on my head!
Date published: 2019-12-26
Rated 5 out of 5 by from Comfortable and good looking! This is the second One K Defender helmet I’ve owned. I’ve tried a lot of others because I have a horse-stuff buying sickness (LOL!). This is, by far, the most comfortable and good looking helmet I own. Pay attention to whether you need the round one or the oblong one. I needed oblong and was surprised because I’ve never thought of my head being oblong. After measuring it, it obviously is. I love how it fits!! You can’t go wrong... it looks great in the barn and at the shows!
Date published: 2019-12-20
Rated 4 out of 5 by from Great helmet, but chin strap needs work Bought this in a Long Oval, which fits my head perfectly. Very comfortable helmet, and looks great. The harness / chin strap, however, needs to go back to the old design. You can only adjust one side, and even then your adjustments are limited due to the velcro closure. In order to fit around my cheeks and jaw without pinching, I can only close half the velcro. The chin strap is also angled more forward than other helmets, so it sits farther forward on your cheeks and chin. The old One K helmets were not like this. Helmet is great...chin strap is NOT.
Date published: 2019-12-02
Rated 5 out of 5 by from Safety first Just bought this helmet for my daughter. I chose this helmet based on the safety specs and overall look
Date published: 2019-11-15
Rated 4 out of 5 by from Lightweight, stylish Love the removable liner, great for hot climates. I got this to wear on the flat and arena jump schooling. I will wear my Charles Owen for cross country as this seems too light for xc. Love the Navy! Fit seems great, love the chinstrap design.
Date published: 2019-07-23
Rated 5 out of 5 by from Great ventilation and comfort! I was looking for a new helmet because my old one didn't have enough vents and my head got so overheated and I became dizzy while riding. I tried many different helmet brands and this helmet fit me the best. I wanted something that was nice looking for the hunter shows I am in, but I didn't want to spend too much money because I am still growing. This helmet is a great price and is an awesome helmet.
Date published: 2019-07-16
Rated 3 out of 5 by from Great helmet, but poorly angled chin strap I loved the oval helmet, but the chin strap didn't work for me. It is angled too forward for my face. I wish the strap had more webbing on it instead of the stiffer plastic. The helmet fit well and I liked the venting. The small fit me, while the medium was too big and my measurement (6 7/8) was the low end of the medium. I returned the helmet due to the chin strap issue.
Date published: 2019-07-06
Rated 5 out of 5 by from I ordered the Large (Long Oval) since my head measures to 7 1/8 with my hair down and 7 1/4 with it up for shows. I had previously been using a 7 1/4 Charles Owen JR8, but I school in a M/L Ovation helmet with an adjustable dial. This helmet will soon be too big with my hair down, it feels like it will start wiggling once the padding compresses due to wear. With my hair up it is perfect and comfortable enough even in the summer heat - certainly better than my Charles Owen! I bought it as a show helmet so it's all good! Just know it measures towards the larger size, not the smaller one in the range given. This will be especially noticeable when the padding compresses.
Date published: 2019-07-03
Rated 5 out of 5 by from Super Comfortable So happy with this purchase! Very comfortable and vented well.
Date published: 2019-07-03
Rated 5 out of 5 by from Great fit, great quality I bought this helmet a couple weeks ago, so I don't have a ton of experience with it yet, but my head measured exactly at the borderline between small and medium and I got a small to be safe as that is what my old helmet was. The small fits great and the dial used to adjust it is a great addition for people like me who didn't know if the small would be too small. Fits great, feels sturdy and I show jumpers and this is totally suitable for local jumper shows. I wouldn't suggest it for rated just because of the dark grey color (not black)
Date published: 2019-06-02
Rated 5 out of 5 by from Perfect for hard to fit daughter This is the ONLY brand of helmet that fits my 10 year old with a round head. We have tried all the others and this fits like a glove. Lightweight, cool in hot temps and low profile. We just purchased her a second in navy and it is gorgeous!!
Date published: 2019-05-22
Rated 5 out of 5 by from Excellent fit I transitioned from a Samshield to the One Ks after getting sick of spending $400 every time I would hit my head badlyl enough to replace my helmet. The finish is very clean, there are more vents, and I'm a 7 so the Medium fits great. I tried the regular (round) fit.
Date published: 2019-01-24
Rated 5 out of 5 by from Great fit I bought this helmet for hunter shows and it fits perfectly. I have struggled to find one that fits and looks great and this one has met all my standards
Date published: 2018-10-22
Rated 5 out of 5 by from Cool helmet and light Love love this helmet! Super light weight and ventilation is great! I’m in Texas and it is hot! I’ve always worn and love Charles Owens but the price tag and they are hot. I have the oval one k and it fits me fabulously!
Date published: 2018-10-08
Rated 5 out of 5 by from Love the helmet For the last several years I bought this helmet (one just for shows, one in Blue and one for every day riding). They have always started off tight (I have a bony growth like a small horn) but use to it. So when the oval one was offered I figured it would not be as tight. Well it ended up being really loose to the point I couldn’t bend over it would slip right off. I still love this helmet but the oval one just didn’t fit like I wanted It to. Though I might try downsizing next time....hmmm
Date published: 2018-09-27
Rated 4 out of 5 by from Love it Very comfortable, very nice little looking helmet. I like the fact that the inside liner is removable for washing. This helmet seems like more for my money. The vents keep my head cooler, too. My only complaint is the chin strap sits at a funny angle.
Date published: 2018-09-16
Rated 5 out of 5 by from LOVE! I am a long oval FAN! CO helmets gave me a headache. GONE with this shape! The brown is stunning!
Date published: 2018-09-13
Rated 5 out of 5 by from Love it I love this helmet, it fits and looks great. I bought the regular round.
Date published: 2018-09-10
Rated 5 out of 5 by from Stylish comfortable helmet Been searching for a helmet that fits my oval head and well this not only fits well , but it’s really comfortable and stylish !!
Date published: 2018-09-10
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Q & A
Videos
One K Defender Matte Helmet Review
Katie from SmartPak talks about why she thinks the One K Defender Matte Helmet (http://bit.ly/1F0MsaV) is so smart. The smartest reason to get yours at SmartPak? Free Shipping Both Ways! At SmartPak.com, you’ll get free shipping every day on all orders over $75 and free returns on all sized items. Just another way it pays to be $mart.
How to Shop for a Helmet
Have you ever struggled with the idea of buying a helmet online? Watch this video for tips & tricks on getting the right helmet fit.

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