This is a great insulated swim cap!   It keeps your head warm while swimming, and doesn't pull your hair while putting it on.  I swim in an outdoor pool in CA winters, and my head stays nice and warm.

excelant

I use these caps, covered with a brightly colored latex cap, to improve my comfort when swimming in the San Francisco Bay.  Commonly the water temperature is 52 - 54 deg F, and I don't wear a wetsuit.  At those temperatures, it feels much better to be losing heat from somewhere other than your head.  I've worn this cap down to temperatures of 50 deg F and found they work flawlessly.  
My only caveat is that they are not in accordance with English Channel rules, so be sure this cap will be accepted in the swim you are training for.

I love this cap.  It is much better than the ones with a chin strap.  
I wear another cap over it to keep it in place, and it does keep my head warm!

This is my second cap of this kind. The first one lasted several months, which I think is good, given that  I swim in a pool 4-7 times a week. It fits well and does keep my head warmer than other types of caps. Recommended.

The cap itself is great, and the service before and after purchase was good. Unfortunately the cap was way too small (and unforgiving) for my size 7 1/8 (an average sized head) noggin.