5.The package comes with three rubber ring inserts to provide a snug fit and protection of the mounting surface. Rubber rings diameter are: 0.5'' / 0.87'' / 1''. It is fit for most handlebars of bicycle/motorcylce,ATV. 4.This 1 inch ball mount handlebar base compatible with RAM Mounts and socket arm component, including double socket arms, navigation mounts, action camera mounts, bike & motorcycle phone mount holders and others electronic device holders. Suitable for bike, bicycle, motorcycle, stroller, mountain bike, dirt bike, road bike, golf cart, electric scooter, ATV, etc. 3.This handlebar mount ball holder ball mount adapter made of high quality aluminum alloy.It is durable and reliable in the most demanding environments. The ball joint adopts CNC-molding design, with anti-slip performance. 2.This ball mount phone holder 1 inch ball mount fits to bike/motorcycle/ATV handlebars from 0.5" to 1.26" in diameter. 1.Our ball mount base1 inch ball clamp utilizes rubber-insert and lockbolts( Tool-less installation )to prevent loosening in high vibration for mounting to motorcycle,ATV or bike handlebars as well as other round rails within the insturcted dimensions.