Attach Your Gopro To Roll Bars, Tubes And More. Fits 1.4" To 2.5"(3.5cm To 6.35cm) Diameter Tubes. Perfect For Clamping To The Metal Or Plastic Radiator Cap Of Karts, Or To Bike Frames, Bumper Bars, Roof Racks And More. The Included 3-Way Pivot Arm Makes It Easy To Get The Perfect Angle For Every Shot.