The Gul Response 3/2mm Back Zip Wetsuit is the ideal wetsuit for people wanting the combination of value for money and performance. The Response is constructed using flatlock seams and X-Flex super stretch panels for comfort with seam free seat construction. With incredibly durable Powertex4 knees for a longer lifespan. Product Information: Product Code: RE1319S20-BKBK Flatlock: Seam construction. X-Flex: 150% Super Stretch main body. D-Flex: Durable lower body panels. PK: Easy entry back zip system. Powertex4: Knees for flexibility and durability. Pro Neck: Seam free neck seal. Mesh: Chest and Back to prevent wind chill. Non-petroleum based neoprene.