This 1'' ball mount base made of high quality aluminum alloy material with TPU ball, integrated molding, smooth surface and solid body. The ball head has a non-slip design, allowing your device to be securely attached to it. This 1'' ball mount base with 10mm hole. Suitable for installation to rear-view mirror frames or other bolt heads within the stated dimensions.The 1 inch ball mount compatible with RAM B size 1'' ball socket arms. Also works for other devices with 1'' swivel ball mounting pattern, Such as some navigation mounts, action camera mounts, mobile phone holders, etc. Suitable for installation on bike, bicycle, motorcycle, stroller, mountain bike, dirt bike, trek bike, road bike, golf cart, electric scooter, ATV, etc. Transition: 1cm=10mm=0.39inch Please allow 1-3mm error due to manual measurement. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thanks very much!