blueseventy PZ3TX Men's Swimskin Features four different fabrics designed for optimal compression, fit and speed. The front fabric is lightweight and hydrophobic COMPRESSION Provides extraordinary elasticity, optimal muscular compression, an excellent fit, great coverage and exceptionally breathable. LOCKING ZIPPER Advanced YKK auto locking zipper (no string or lanyard needed). This unique zipper system reduces drag, is faster to remove and due to its lightweight and flexibility, more comfortable DURABILITY Retains shape and fit longer. White heat reflective fabric in the upper back, highly compressive to reduce drag, while allowing optimal thermoregulation for warmer swims. The lower back uses ultra-thin fabric further reducing the weight while maintaining superior heat retention and elasticity.