Sealed Warmth and Durability. If you're looking for the perfect balance of warmth, performance, and value, the HydroFlex Series is the perfect fit. Featuring our exclusive Thermo Dry Celliant (TDC) infrared interior, it helps keep you warmer by reflecting your body's natural infrared energy back to your core. Combined with sealed wrist cuffs, ankle zippers with inner dams, triple-glued and blind-stitched seams, and compression-resistant neoprene, the HydroFlex Series is built to deliver outstanding warmth, comfort, and durability dive after dive.