REI Co-op On The Trail Cap
Keep a cool head on your trail runs with the REI Co-op On The Trail cap. It has a stretchy and low-profile fit, with UPF 50+ fabric and laser-cut ventilation holes on each side for airflow.
- Low-profile, 5-panel crown made with stretchy polyester fits snug onto your head
- Fabric wicks moisture and dries quickly to help you stay cool and comfortable on the trail
- UPF 50+ sun protection
- Laser-cut ventilation holes on the sides enhance breathability
- Interior sweatband helps keep sweat out of your eyes
- Flexible brim and rear bungee closure with cordlock let you adjust the fit
- Bungee closure wears softer than traditional cap closures
- Hand-wash with cold water; line dry
- Contains materials that meet the bluesign® criteria
- REI Co-op brand is certified to The Climate Label; we actively fund efforts to reduce carbon emissions across our business and support climate projects around the world
Imported.
View all REI Co-op Men's Ball CapsBest Use | Running Trail Running |
---|---|
Hat Style | Ball Cap |
Fabric | 96% polyester/4% spandex (bluesign approved) |
Lining Fabric | Interior headband: 91% polyester/9% spandex (bluesign approved) |
Sun-Protective Fabric | Yes |
UPF Rating | 50+ |
Moisture Wicking | Yes |
Quick Drying | Yes |
Visor/Brim | Yes |
Head Circumference | 21.5-23.5 inches |
Length of Bill | 2.5 inches |
Gender | Unisex |
Sustainability | Contains materials that meet the bluesign® criteria From a Climate Label Certified brand |
S | M | L | XL | One Size | S/M | L/XL | |
---|---|---|---|---|---|---|---|
Head Circumference | 21.5 - 22 | 22 - 22.75 | 22.75 - 23.5 | 23.5 - 24.2 | 21.5 - 23.5 | 21.5 - 23 | 23.25 - 24.25 |
Sizing Notes
All measurements are stated in inches.
Better gear is built together
From feedback to field testing, all of our gear is dialed-in by REI Co-op members. Their adventures informed every stitch and detail—making for better, longer-lasting gear.


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comfortable and light
Comfortable, light, I really like the color and shape.
Great hat if you like great hats.
I love this hat. I buy it every spring when a new color comes out. I'm not kidding when I say I own twenty of them and I've gifted probably 10 more. Its gone up in price by 10 bucks which is a shame but whatever. More importantly though, the logo keeps getting bigger and bigger every year. Dear REI, STOP this logo nonsense! This hat is perfect. Love you, but I don't need to be a walking billboard for ya. Not all of us live in Boulder. Simple hat, one color, minimal logo. Don't mess this up for me. Love, Spencer
Best lightweight outdoor cap I’ve owned.
This is my go to hat for any outdoor activity and travel. I have owned a few over the past 7 years or so. Sometimes they fly off into the ocean ¯\_(ツ)_/¯ . It is super comfortable, dries fast, easy to wash, bill keeps its shape, the rubber sincher holds well after years of use. I liked the previous year colors and logo better.
Best hat ever??
I love this hat so much. I use it for everything, even casual wear, it fits under my bike helmet comfortably, and it's so lightweight and comfortable. It's ruined other hats for me. Very easy to clean and dries quickly. I love the design and shape of it too, it doesn't make my head look too big
Great for larger heads
Biggest, comfortable hat that is so light weight. The average garment fit my head circumference so finding this one that does is a game changer for hiking.
Great while on my walks.
I have 2 of these hat's. There the best hat's I've worn. I don't have to worry about them coming off when it's windy. The material is absorbant.
Light weight and flexible
Light weight and flexible bill. I've never had a hat like this and it seems thoughtfully made. I like the back elastic too.
Great success! I like!
Love this new running hat-much more breathable than ones I’ve worn in the past!
Awesome Hat!
I bought this hat to replace my Boco visors which I really like but they didn't give me full head coverage in the hot Hawaii sun. Now that I've been wearing it for a few weeks I'm not sure that I'll ever switch back. For one, when I'm running I barely notice that I'm wearing a hat and the sweatband has done really well. I love the bungee closure cord. The one I bought was on sale so the risk was minimal and the result has been great.
Most comfortable cap ever!
Most comfortable cap I’ve found so far! I have long thick hair so it’s hard to find a cap that’s lightweight for Summer but will also hold my hair back off my neck. I walk a lot with dogs, hike, and needed a general Summer-weight cap. I love that it packs easy in a small bag or pocket, too. I got used to wearing more masculine baseball and trucker caps but this is so much more feminine. Love it.