Snap BMX Products S2 Fixed Seat Post Clamp.  Precision CNC machined from USA mill certified 6061-T6 billet aluminum. Stylish design.  Comes with 18-8 stainless steel screw.  Size : 28.6mm (large hole) fits frame post.  Small hole fits 25.4mm seat post.  Color - Blue Anodized.  Weight - .96 oz.