Box Two Quick Release Seat Clamps are cold forged and CNC machined from 6061-T6 aluminum alloy. Weighing in at just 27 grams/ 0.95 ounces in the 31.8 size, they are as lightweight as they are tough. The head of the quick release lever and the face of the clamp are given a proprietary low-friction surface treatment that ensures smooth lever action for the life of the clamp, without the need for a bushing. Meets or exceeds ENM standards. Colour: Grey, Blue, Black, Red, Green, Yellow; Size: Small, Large