This top-of-the-line 2mm hood features TDC Thermo Dry Celliant, Xcel's warmest inner lining ever. TDC features mineral-enhanced smart fibers that recycle body heat into infrared energy for greater warmth, increased endurance, faster recovery, and enhanced overall performance. The Drylock TDC hood also features a double flap neck dam to tuck inside and outside your wetsuit collar, a sturdy Texture Skin bill, SmoothSkin face seal with an adjustable elastic cord/cinch, and outer Texture Skin for excellent wind resistance. Premium 100% UltraStretch neoprene; glued & blindstitched seams finished with inner Thermo Dry seam tape.