The DUI FLX EXTREME Drysuit. DUI’s most popular drysuits for exploration divers! The trilaminate fabric consists of polyester/butyl rubber/polyester with the butyl being slightly thicker than the TLS350 - making it more puncture resistant. We then add Cordura® overlays on the legs for added durability. Yet it’s the outer fabric that feels soft to the touch and supple just like your favorite pair of jeans.