The HyperFreak Fire Series builds upon the flexibility and comfort of the HyperFreak legacy with increased warmth and durability. Built with TechnoButter 4 and the buttery soft, stretchy, and heat-recirculating TB4X neoprene made of 90% or more recycled fibers in the liner fabrics. Paired with TB4 Firewall to reflect chest, back, and leg warmth, red-hot heat plus water-tight seams have created a new cold-water legend.