RAM-D-254U - Round Base 62mm AMPS - D Series (2.25" Ball) vehicle-agriculture if your arm uses the

if your arm uses the smaller 1" B ball

giving it a B Size ball for use with any RAM double socket arm

and vehicle headrest rails where there's no handlebar to mount to

it covers the Montana 600

RAM-D-254U - Round Base 62mm AMPS - D Series (2.25" Ball) vehicle-agriculture if your arm uses theRAM D 254U RAM Round AMPS Plate with Ball The RAM D 254U is a 63. 5mm (2. 5") round AMPS plate fitted with a D size 2. 25" rubber ball. It's the round base needed to mount a D Series arm to most RAM cradles the larger RAM D 202U won't fit these, so this smaller plate is the one to use when connecting to AMPS pattern device holders. Key Features 2. 5" round plate connects to RAM device holders with the universal AMPS hole pattern D size 2. 25" RAM