Box One Quick Release Seat Clamps are cold-forged, and CNC machined from 6061-T6 aluminum alloy. A quick-release lever makes adjusting your seat height quick and easy. Weighing just 28 grams/1 ounce in the 31.8 sizes, its as lightweight as it is tough.The head of the quick-release lever and the face of the clamp are given a proprietary zero-friction surface treatment that ensures smooth lever action for the life of the clamp without the need for a bushing.