This is a complete system to mount the Magellan 300 315 320 GPS units to any handlebar ranging in diameter from 3/4 inch to 1 1/4 inch.  This kit includes the RAM Magellan 300 315 320 cradle (NAMT-1-7356), RAM Universal Handlebar Mount (NAMT-1-7301), RAM Standard Arm (NAMT-1-7303), and  RAM Diamond Adapter Plate (NAMT-1-7302).  This kit is priced below the total sum of buying the components separately.