RAM Backing Plate Adapter2.10 x 2.60 steel backing plate with hardware and two-hole patterns: 4-hole AMPS pattern with #8-32 threaded holes, and 4-hole 2″ x 2.5″ pattern with #10-24 threaded holes. Included hardware can attach to ball bases such as RAM-202U and RAM-202U-225.Features:2.10″ x 2.60″ steel backing plate with hardware attaches to a variety of RAM Mounts ball basesIncludes screws and lock washersBacked by a lifetime warrantyHardware Included:(1) 2.1″ x 2.6″ Stainless Steel Backing Plate(4) #10-24 x 1″ Machine Screws(4) #10 Lock Washers(4) #8-32 x 1″ Machine Screws(4) #8 Lock WashersSpecifications:Product Dimensions: 2.1″ x 2.6″ x .15″Hole Pattern: 4-Hole AMPS: 1.181″ x 1.496″ (#8-32)/1.5″ x 2″ (#10-24)Materials: SteelWeight: 0.3 lbs