The Rip Curl Heat Seeker hood offers maximum protection and stretch and warmth. This 3mm hood is equipped with E6 Flash Lining and V2 Flex Energy, a revolutionary neoprene that generates heat when stretched. As you move through the water the Flex Energy lining will activate and heat up so you can keep active and warm out on the water. The E6 Flash Lining has 20% more stretch than E5 and has improved drying properties. This updated technology paired with the smooth face seal is perfect for long sessions in cold water.