This RAM® Track Ball™ bundle includes the RAM® Track Ball™, the RAM® Double Socket B Size Arm, and the RAM® Round Plate with Ball & Mounting Hardware for Garmin Striker and other fishfinder models. The RAM® Track Ball™ consists of a B size 1" rubber ball molded to a high-strength composite base, a rubber friction washer, and a stainless steel T-bolt for sliding into virtually any track system. Simply insert or slide the RAM® Track Ball™ into your track and twist the ball clockwise to tighten in place. Twist counterclockwise to loosen or adjust the ball. The included, RAM-B-201U consists of a medium length double socket arm that accommodates 1" B size ball bases, device holders, and adapters. The easy-to-adjust knob allows for near-infinite adjustability for your connected device. The 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™ and Striker™ 4 Series.