This Speedsuit features the fastest and most drag reducing 100% textile swim fabric available. Knee length legs are quick in transition and comply with new speedsuit rules for Ironman and Ironman 70.3 racing. Yamamoto BRS TX2S: Most Advanced streamlining 100% textile fabric available. BRS TX2S Fabric is extremely lightweight and water resistant. WTC Compliant: Follows new rules for speedsuits outlined by World Triathlon Corporation effective September 1, 2010. Garment streamlines triathlon clothing pockets, mesh, etc, and is meant to be REMOVED after swimHigh Spandex fabric inserts allow tight but not constricting fitBettyFit Womens specific design on womens modelsFabric 1: 80% Polyester, 20% Polyurethane Weight 180 gmsM2Fabric 2: Nylon 71%, Spandex 29% Weight 161 gmsM2FABRIC 1 is FINA approved, but MAKO TXT is NOT designed for pool or open water swim competitions unless specifically approved by individual race directors. World Triathlon Corporation, parent company of Ironman, Ironman 70.3, Irongirl, and IronKids races.