This skull cap fits the bill for what a winter under cap should do. It retains heat remarkably well, It stays put and doesn't ride up. It is lightweight and comfortable.
I use it in cold and very cold weather under an insulating hat and not a helmet. I have also taken to using it off the bike too in combination with another hat and sometimes alone.
I bought it on sale, so it was an excellent value. I am not sure what the normal retail is, so that calculation would have to be made.
This Pearl Izumi Barrier Skull Cap has a nice snug fit to it. I especially like the lower sides that fully cover exposed ears! There is a ponytail cutout in the back that I have no use for, maybe if my hair comes back I'll be able to make use of that? I wear this for any ride below 50F, down to about 30F. Below that I switch to a balaclava.
Fits nice, covers just enough and resists most of the wind while being breathable. This one will last you.
I got this to keep my ears warm kept creeping up above my ears
I wear my hair in a ponytail and most caps tend to creep up. This one stays put.
One size fits most? Maybe most children and some women. Did not cover ears at all. Gave it away to my little sister. She likes the hair hole.
