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One K Defender Matte Helmet

One K
- Item #21807
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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
96% of customers would recommend this product to a friend!
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One K Defender Matte Helmet is rated 4.7 out of 5 by 90.
Rated 5 out of 5 by from Love this helmet! Great fit, true to size. Love the look of this helmet, low profile. Converted from a CO, and this One K looks much less bulky on my head than the CO.
Date published: 2016-10-10
Rated 5 out of 5 by from So Comfortable! I bought the One K Defender Matte Helmet a few weeks ago after studying and comparing all of the helmets and I extremely happy with my purchase. It is cool, comfortable and I don't get headaches while wearing it. I highly recommend :)!
Date published: 2016-10-04
Rated 5 out of 5 by from Great for a child also We bought this helmet for my 12 yr old after she had a charles owens jr8. This helmet is very comfortable and she loves it. It fits perfect looks great.I just bought one for myself. Cant wait til i can use it! I love my Samshield and use it for shows.
Date published: 2016-09-22
Rated 5 out of 5 by from Nice helmet Very comfortable, finally found s helmet that works for me.
Date published: 2016-09-08
Rated 5 out of 5 by from Very Happy! Just purchased the navy in medium (wear a 6 7/8) and it fits perfect and very comfortable. Very stable on my head versus my Charles Owen AYR8. I really like the placement of the harness directly under my chin versus further down with my Charles Owen. Definite buy.
Date published: 2016-08-18
Rated 5 out of 5 by from Great helmet I bought this helmet for my granddaughter and she loves it.
Date published: 2016-08-12
Rated 5 out of 5 by from I love this helmet! So happy with my purchase! I had wanted to get something a little classier for dressage/stadium than my CO skull cap. The Samshield was exactly what I wanted, but I was so sad to try it on and have it look like a mushroom on me. I figured since the One K was pretty much the same silhouette that it would have the same effect on my head, but it was so speak. I love that I can wash the liner and that I can just snap a larger or smaller one in depending on if I want my hair up or down. Although, I would love to see some for size options for the liners, the small is to tight with my hair up and the medium is a little too big (though I'm sure I could add some extra padding if I wanted to commit back to riding with my hair up). I LOVE the ventilation, my helmet doesn't get nearly as sweaty or smelly as any of my CO helmets. I also love that the helmet doesn't scratch very easily. Only other complaint is that I do wish the chin strap could go just a little tighter on the smaller helmets. Overall, this helmet is fabulous and I haven't seen anyone that's head isn't flattered in it! They are so versatile, they are so popular in dressage and eventing and are even making there way to the hunter/jumper rings! Also the number of top athlete's riding in these helmets give a little piece of mind. A +!
Date published: 2016-08-10
Rated 5 out of 5 by from My new favorite helmet This helmet is stylish and comfortable! It is lightweight and it is ventilated nicely.
Date published: 2016-07-25
Rated 5 out of 5 by from Great new helmet Bought this for my daughter after working with the incredibly helpful staff from Smartpak at Rolex. She loves the fit and feel and I love the security and design!
Date published: 2016-07-20
Rated 4 out of 5 by from Beautiful helmet, Great fit I absolutely loved this beautiful helmet, and would have kept it, but the chin strap was a no go for me. The fit was perfect, the blue color was a delight. I ride trails only, and wanted a new, well vented helmet. At first I was "oh this is it!" ( I ordered 3 different helmets to try) but I was sad at the chin strap. I spend several hours at a time out riding the mountains, and was afraid this would cause me great discomfort. I suppose if I rode only an hour it would be ok, but it was very distracting. I'm going to say this is a nice oval shape. I would definitely have kept it, but for the chin strap. I also had my horse girls try it, they loved it too, but again the chin strap (we all trail ride) So that's why 4 stars, it would have easily been 5.
Date published: 2016-07-14
Rated 5 out of 5 by from Very comfortable Light weight. Great fit. Would recommend to my friends
Date published: 2016-06-17
Rated 5 out of 5 by from This is the most comfortable helmet I have ever worn!
Date published: 2016-06-17
Rated 4 out of 5 by from similar style pricier helmet - not as customized This OneK is a similar build to the Samshield for 1/2 the cost ... certainly the customization of the Samshield (specific hat sizing vs sm/med/lg) is nice - and they add a few side products which might be nice - winter warmers) ... but for anyone budget conscious, this one fits the need with a much more affordable price!And yes, if you are on the cusp of the top sizing for your head measurement - order the size up.
Date published: 2016-06-03
Rated 5 out of 5 by from Best buy for a nice looking helmet Great fit, comfortable, doesn't give you a "bucket head," phenomenal buy for the price.
Date published: 2016-05-15
Rated 5 out of 5 by from Very comfortable I have ridden several times in this helmet and my head stays cool. Very comfortable I don't mind wearing it for several hours at a time!
Date published: 2016-05-02
Rated 5 out of 5 by from great helmet at a more reasonable cost I love this helmet! Super comfy -- just put it on and forget about it. It looks stylish and "show worthy" without a price tag north of $400. Definite thumbs up.
Date published: 2016-04-25
Rated 5 out of 5 by from Comfortable, looks sharp Good buy. Comfortable fit and doesn't make your head look like a giant dome.
Date published: 2016-04-19
Rated 5 out of 5 by from Comfy Time for a new helmet brought me shopping here, since I'm a SmartPak customer.I liked the look and venting features advertised, since I live in a very warm, humid area, so I ordered the One K. Love the fit, it is snug but not uncomfortable, well padded and appears to breathe fairly well.
Date published: 2016-04-19
Rated 4 out of 5 by from Nice fit Very comfortable (once I traded my L for and XL) and cushy liner wicks sweat away quickly. Large enough for my hair to be up or down in a pony tail.
Date published: 2016-04-18
Rated 5 out of 5 by from Super Comfy! This helmet is super comfy and light! And the vents help a lot especially when the weather gets warmer.
Date published: 2016-04-07
Rated 5 out of 5 by from Very comfortable helmet. I have a very hard time finding helmets that a large enough, yet do not have a huge profile. I have always worn Tipperary helmets, but have been unable to find a T2 lately. After tons of research I tried this One K. The XL did fit comfortably, but the helmet profile just appeared huge. I returned it for a L, and tried it with an XL liner as many people had advised. The fit feels the same, and it feels much less cumbersome overall. Very comfortable helmet, well-ventilated, and I quickly got used to the more forward chin strap.
Date published: 2016-03-21
Rated 5 out of 5 by from Amazing I just received this and I love it! It is gorgeous.
Date published: 2016-02-25
Rated 5 out of 5 by from Great helmet! Great price! I had an IRH helmet before this for awhile and recently bought the One K Matte Defender and I love it. It's a great price, super comfy and look great!
Date published: 2016-02-24
Rated 5 out of 5 by from LOVE this helmet! I've had this helmet for about a year and a half and I originally bought it because my CO GR8 didn't have any ventilation for summer riding. Out of all the helmets I tried, this one fit the best and had amazing ventilation. I can actually feel breeze when I ride in this helmet and it doesn't leave my hair all sweaty after I'm done! Definitely recommend this helmet!
Date published: 2016-01-05
Rated 1 out of 5 by from Looks great! .. But what about protection??? Falling is inevitable. It's just a matter of when and what helmet you will be wearing when it happens. The helmet itself has a nice look to it and is comfortable to wear but during a fall, the protection that it provides is very slight. It held up just fine and the plastic shell remained intact, however, it was absolutely painful. The helmet itself might be so uncomfortable during a fall that it causes more concussion than no helmet at all would have, as my head slammed into the arena sand. I've worn a variety of different brands and had plenty of spills as an exercise rider for racehorses -- not that I love to admit the falling part -- but if you haven't fallen, then you likely haven't ridden enough. Anyway, this helmet hurts. It doesn't get a recommendation from me. For your safety, you might consider looking elsewhere.
Date published: 2016-01-01
Rated 5 out of 5 by from Still digging this helmet I have the Black Matte for Hunters and love it but i think I may have to get it in Navy too, to match my Jumper attire :) Price wont break the bank either.
Date published: 2015-12-22
Rated 5 out of 5 by from Love! I bought this helmet for my daughter who is in pony club and wants to start showing more this upcoming year. She loves it! It is very comfortable and I wish my head was a tad smaller so I could share with her. I will be ordering one for myself in the near future.
Date published: 2015-12-15
Rated 5 out of 5 by from I love this helmet!! This helmet fits like a glove!! I absolutely love how sleek and low profile this helmet is. I have a slightly oval shaped head and my other helmet didn't fit the best so I went looking for something new. I came across this one and immediately fell in love. I ordered this in a large, but it was just a tad snug. I ordered and XL liner and snapped that in instead and now it fits perfect. I am in love with this helmet!
Date published: 2015-12-03
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
  • 2016-10-22T11:44CST
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