*The Psycho Tech is built for the absolute harshest conditions and allows the user to surf for hours on end.* O'Neill's Psycho Tech range focuses on ultimate warmth and durability with high-performance materials and water-tight double-sealed stitchless seams. The TB4 Firewall technology radiates throughout with TB4 Duraskin Air Firewall in the chest and back to shield against the cold while retaining and recirculating your body heat. Designed to keep you in the water longer, toasty, and stoked.