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 fits to most bike,motorcycle,ATV,Stroller handlebars and rear view mirror poles. 4.This 1 inch ball mount handlebar base compatible with RAM Mounts and socket arm component B size, including double socket arms, navigation mounts, action camera mounts, bike & motorcycle phone mount holders and others electronic device holders. 3.This phone mount ball 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 1 inch ram mount motorcycle ball mount bracket fits for handlebars or rails from 0.5" to 1.26" in diameter. 1. Our ball mount base 1 inch ball mount phone holder ball mount adapter utilizes rubber-insert and lockbolts to prevent loosening in high vibration for mounting to motorcycle or bike handlebars as well as other round rails within the insturcted dimensions.