The RAM fork stem base adds a B size 1 inch rubber ball to motorcycles with a compatible hollow cylindrical fork stem. It provides a clean central starting point for a RAM phone, GPS, camera, or other device mount while keeping the handlebar area uncluttered.Compatibility Fits cylindrical fork stem bores from 12 to 38 millimeters Equivalent fit range of approximately .5 to 1.49 inches RAM B size 1 inch rubber ball Compatible socket arm and device holder sold separately Features Marine grade aluminum construction Expansion plug hardware included Recommended capacity of 2 pounds for standard use and 1 pound for demanding conditions Backed by the RAM lifetime warranty Fit and installationThis base requires an accessible hollow cylindrical fork stem. Measure the internal bore before ordering. Confirm steering, ignition, tank, and instrument clearance through the full range of motion after installation.