The IR Neoprene Short Liners are cozy, above the knee, 1mm thick neoprene "fuzzy rubber" shorts. Great for additional warmth or padding when needed in cooler water or temperatures. Slip them on under any pair of river / board shorts or swim trunks. Or just sport them on their own like your dad did! Ideal for kayaking, rafting, canoeing, SUP, fishing, kiteboarding, surfing or anytime you need a little bit of warmth without adding bulk.