This suit is lightweight yet extremely warm. Rip Curl's exclusive 100% E5 flash lining is as flexible as traditional double lined neoprene allowing unrestricted stretch and warmth on the entire suit. 100% external aquaban plus tape and internal E5 flashlining tape in the arms provides maximum durability and while maintaining insane flexibility. E5 Flash Lining Internal Stress Point E5 Flash Lining Tape 100% External Aquaban Plus Tape Glued And Blind Stitched Back Mesh Panels