The GoPro Roll Bar Mount Kit is designed for quick-release for your GoPro camera on to tubes/frames ranging from 1.4" to 2.5" (3.5cm - 6.35cm) in diameter. Perfect for clamping your camera to the radiator cap (both metal and plastic caps) on karts. You can also clamp to bike frames, bumper bars, ski/surfboard racks or anything else that is in the size range above.