Immersion Research Thermo Cap

Comfortable

Used this under my helmet in 60F water and 60F air temp Could definitely go colder Fit nicely under my WRSI helmet Will be using for my late spring / early fall runs in western PA.

Good product - a bit small

It’s well made and of a nice quality. It’s a little small. My head measured within the range for the smaller size but it’s a really tight fit. I’d go with the bigger size if you’re towards the top of the range for the small.