I have an average sized human head and I found the fit of this cap to be pretty bad. As others have mentioned, the elastic is tight and did indeed give me a headache on a ride. At the same time I found the overall volume of the cap to be too large. I can actually pull it down to completely cover my ears. I thought the brim was also pretty big and view obstructing. The mesh material is nice and cool so that's good at least. Guess I'll go back to my Giro.
I was looking for a billed cap that a fellow rider says is good for sweat management for the hot and humid SE Texas summer. This cap has a mesh cover for improved cooling but keeps the sun off my balding scalp. The bill allows sweat to mostly drip away from my cycling glasses depending on exact weather conditions and the tilt of my head. I just rinse in plain tap water and air dry after such rides to reduce wear and tear from heavy laundering. Might be considered a bit pricey if bought at regular price.
It was way too small - a big disappointment. I previously owned and used another simiar cap; one I presumed to be identical. The old cap fit great. I hoped it would stretch after a few uses but eventually stopped using altogether.
While I am usually a Castelli fan, this cap is too tight on my head. FYI: My head is relatively large, about 22.5 inches. I wore it twice and got a headache both times. Had to take it off. If you have a smaller head, it might work for you.
Good cap for mild days. The mess top wonï¿½t do anything for rain and definitely not a cold weather cap.