BILLET BMX SHIELD SEAT POST CLAMP 31.8mmThe BILLET BMX Shield Seat Post Clamp is an upgrade over your standard basic clamp. The outer shape of the clamp matches our popular shield design. We use a Stainless Steel Bolt and Cylinder so the aluminum clamp does not get stripped if overtightened. It is fully CNC machined and made out of 6061 T6 Billet Aluminum. The clamp is then anodized and engraved. Upgrade your bike today with Billet BMX. 31. 8mm (1 1 4") with No Shim 6061 T6 Aluminum Full