TYR's exclusive collection of Durafast™ suits are high performance polyester. Built with 100% polyester, Durafast is 100% chlorine proof for 72 hours of exposure. This durable fabric lasts 20 times longer than traditional swimwear. Durafast provides 100% colorfastness in addition to unsurpassed sun resistance. And TYR's 4-Way Stretch Technology helps Durafast swimwear maintain its excellent fit.