The large version of the RAM Mounts Torque Handlebar Mounting Base features a 1' B-size RAM rubber ball and is compatible with tubes/rods/rails from 1 1/8 to 1 1/2' in diameter. Sizing inserts are included to provide a tight fit while protecting the mounting surface. The large mounting base also includes nylon-insert lock nuts to prevent loosening in high-vibration environments. It supports up to 2 lb in standard use and 1 lb in heavy use.