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 aiming easy, so you can achieve the perfect angle for every shot.