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 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.