The Author QR seat clamp. With its ergonomic lever it’s easy & quick to adjust the seat height. Lightweight design and durable alloy material. For frame seat tube d. 40,8 mm (seatposts around 33,9 mm). Ergonomic lever. Material: clamp and lever AL6061 / steel axle. Weight 52g. where to buyphotogalleryproduct options Photogallery Product options black-glossyd.40,8mm = UA#30052036