The RAM-B-138-GA57-225BU consists of a double socket arm, 2.5" diameter round base with the universal AMPS hole pattern, diamond adapter base, custom high strength composite cradle and steel backer plate for the listed compatible Garmin nuvi series. Designed into the mount is a 1" diameter patented rubber ball and socket system with adjustment points at the base and cradle. With a twist of the arm knob, you can move the flat surface nuvi mount to your optimum viewing position. 

Compatible Devices:
Garmin nuvi 2557LMT
Garmin nuvi 2577LT
Garmin nuvi 2597LMT
Garmin nuvi 2598LMTHD

Material: 
High Strength Composite & Powder Coated Marine Grade Aluminum 

Ball Size: 
1" Rubber Ball "B" Size 

Note: 
The "U" in the part number reflects product packaged in poly bag.