The Garmin Strap Base Tube and Rail Mount fits a rail diameter from 1.0" to a maximum of 2.1". The 1" rubber ball is at a right angle to the mount base placing the ball at a right angle to the rail.

To mount this base, first place the Garmin metal plate on the rail and then wrap the metal clamp strap around the rail and plate. Tighten the screw knob on the metal strap with a screw driver until the strap has a firm hold on the rail.

NOTE: This base will attach to any of the Garmin or RAM Mount 1 inch ball socket arms.