The Flex Gi This may look like any other gi, but it is the first of its kind. The Flex Gi features a Pearl Weave jacket and Twill pants made from a 50% cotton, 47% polyester, 3% spandex blend that delivers true 4 way stretch. Engineered for jiu jitsu athletes who rely on movement, this BJJ gi bends, flexes, and adapts with your transition