Hope Seat clamp - 31.8QR, 34.9QR, 34.9, 36.4 "Secure, CNC machined clamp" Technical specifications: Material: 6061 Aluminium Clamp: 31.8mm, 34.9, 36.4 mm Height: 17.2 mm Mounting: Allen Bolt (34.9, 36.4), QR (31.8, 34.9) Color: silver, red, purple, blue, orange and black Weight: about 26g (manufacturer) Material: 2014 T6 Aluminium and Brass