XCSOURCE New 20mm Picatinny Weaver Gun Rail Mount for GoPro Hero 2 3 3+ 4 Camera OS106 Works on all standard picatinny/weaver/1913 rails Comes in hardcoat anodized matte black finish Includes nylon-tipped set screw and is ready to use Compatible with GoPro HERO 2 3 3+ 4 Cameras Matrial: Aluminum