The RAP-101U-G4 consists of a 2.5" diameter round base with the universal AMPS hole pattern, double socket arm and round adapter base that attaches directly to the back of the Garmin echoTM. Designed into the mount is a 1.5" diameter patented rubber ball and socket system with adjustment points at both socket ends of the arm; this with RAM"s rubber ball and socket technology allows for almost infinite adjustment and perfect viewing angles. Included is hardware that is used to attach the Garmin echoTM to the RAM Mount.This mount is compatible with the following electronic devices:Garmin echoTM 200Garmin echoTM 500cGarmin echoTM 550c