?PACKAGE CONTAINED?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''. ?UNIVERSAL COMPATIBILITY? This 0.67" ball mount handlebar base compatible with RAM Mounts and socket component in 17mm/0.67", 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. ?HIGH QUALITY RAW MATERIAL?Sptchapn mount ball base 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. ?LARGE CAPACITY FOR HANDLEBAR?This 0.67" (17mm) ball mount base fits for handlebars from 0.5" to 1.26" in diameter. ?STURDY AND SHOCKPROOF?Sptchapn 0.67 inch(17mm) ball mount holder utilizes rubber-insert to prevent loosening in high vibration for mounting to motorcycle,ATV or bike handlebars as well as other round rails within the insturcted dimensions.