RAM 2.5" Round Base with the AMPs Hole Pattern 1" Ball & Hardware for the Garmin echo 100 150 300cThe RAM-B-202-G4U consists of a 1" diameter rubber ball connected to a flat 2.5" diameter base. This mount has pre-drilled holes including the universal AMPS hole pattern. Included are 3x (#8-32 x 5/8" PH PD Mach Screws) and 3x (#8-32 SS Nylock Nuts) that will connect the RAM-202-G4U to the bottom of the Garmin echo. Compatible Devices: Garmin echo 100 Garmin echo 150 Garmin echo 300cMaterial: 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. Product : RAM MOUNT RAM ADAPTER FOR GARMIN ECHO 100 150 300C Manufacturer : RAM MOUNT Manufacturer Part No : RAM-B-202-G4U UPC : 793442932694