Great undersuits. Have two models: Compact as well as the Extreme +, which I have used on many dives to - 1.5 C with no problems. They work even if wet, are easy to wash and maintain and last a long time. My Compact is 17 years old and still going OK. My Extreme + is a litle bulky and may require a little more weight than other undersuits, even though I normally run my membrane drysuits with the exhaust fully open, but then I don't need a battery and heated undersuit like some of the people I have dived with to stay comfortable in very cold water.