TYR Sport Women s Alliance Durafast Splice Maxback Swimsuit. THE STRONGEST | The Ultimate team suit. 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. Our 4-Way Stretch Technology helps Durafast swimwear maintain its excellent fit.