ROCKBROS Skull Cap Men & Women Thermal Cycling Helmet Liner Moisture Wicking Motorcycle Running Hat,Fits Under Helmets

You can spend a lot of time searching for something else but this is exactly what you need. This hat is warm, very warm. It fits perfectly. It's the right price. Don't overthink it.

Nice and comfortable, relatively thin, works as hoped. Satisfied purchase.

Nice cap for wearing under my bike helmet. It works fine, it’s easy to wash and it’s nice and stretchy. My only complaint is that it is a bit thin. It actually does the job fine except on the frostiest mornings.

I have another helmet liner that has a seam across the front of the forehead & my Full Face (FF) helmet presses against it giving me a headache within an hour. So I've been searching for other liners. This Rockbros helmet liner doesn't have have the seam across the forehead so I bought it over a Christmas sale.My Likes:+ I like the extra thermal liner in the cap. My other helmet liner is just a helmet liner so it doesn't help keep the head warm in cooler weather. This Rockbros liner is great for cooler weather.+ There is no seam running across the forehead!My Dislikes:- My biggest complaint is that the cap doesn't stay put. While wearing the cap alone (no helmet), the cap slides up the back of the head (perhaps it's just my noggin) & exposes the ears. Now granted, my main purpose for the purchase was a helmet liner & not necessarily a cool-weather cap however the idea was floating around in the back of my mind when I made the purchase. Even wearing ear muffs over the cap doesn't quite help. With the inevitable turning & motion of the head, the cap still slides up, hiking the earmuffs up with it, exposing the ears & leaving the earmuffs useless.Wearing a bicycle helmet (a properly fitted helmet does not require the chin strap to be tight) tends to have the same issue as the earmuffs as the helmet is ON the liner. The difference is the chin strap keeps the helmet from falling off however the helmet tends to slide up from the back, tightening the chin strap and making for frequent stops to re-adjust the cap & helmet.Wearing my FF helmet though, the cap can't move.So my initial purpose in the purchase of this liner is still valid (bought for my FF helmet) but the perks of having a Thermal Liner for other uses is not to be. It's more frustrating than not wearing the liner at all when I have to stop frequently & re-adjust because of it's movement.

This is thin enough to wear under your helmet and still keeps you warm

Perfect fit ! I have a 7-7 1/8 head size and it fits right at my eyebrows and well over my ears. Very quality hat that will come in handy for several things.

Keeps head warm and hair out of your face!

110 pound female. Hat was too big for me. Once I had my helmet on it repeatedly kept covering my eyes. I gave it to someone with a bigger head.That being said, it looked like a well-made warm hat.