Johnny Ray Low Profile Push Button Release Swivel Mount For Liquid Crystal Units 2.875" W Hole x 1.250" D Hole. It is compatible with select Computrol/Bottom Line Datamarine Garmin Humminbird Icom Interphase Lowrance/Eagle Pinpoint Ray Jefferson Sitex Vexilar and Zercom units. Some units are compatible but are not a direct match see manufacturer recommendations for installation. The hole pattern in the JR-400 is 2.875" hole width by 1.250" hole depth. Features a maximum weight capacity of 7 lbs. and a 0.875" shaft diameter by 4.000" square mounting area. Molded from DuPont Nylon and assembled with stainless steel springs and screws. Specifications for Johnny Ray JR-400 Low Profile Push Button Release Swivel Mount For Liquid Crystal Units 2.875" W Hole x 1.250" D Hole: Manufacturer: Johnny Ray Quantity: 1 Features of Johnny Ray JR-400 Low Profile Push Button Release Swivel Mount For Liquid Crystal Units 2.875" W Hole x 1.250" D Hole Automatic 360 ratchet rotating 45 position automatic locking top Push button release top; Low profile design - 1" tall Features a maximum weight capacity of 7 lbs. and a 0.875" shaft diameter by 4.000" square mounting area Hole Pattern: 2.875" hole width by 1.250" hole depth Package Contents: Johnny Ray JR-400 Low Profile Push Button Release Swivel Mount For Liquid Crystal Units 2.875" W Hole x 1.250" D Hole Johnny Ray JR-400: Low Profile Push Button Release Swivel Mount For Liquid Crystal Units 2.875" W Hole x 1.250" D Hole