Check the listing for details. RAM-202-225B-2U RAM Backing Plate Adapter.... Color: Black, Condition: New. Listed at 22.94 USD. RAM Backing Plate Adapter... RAM-202-225B-2U Genuine RAM Products! 2.10" 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 INCHES x 2.5 INCHES pattern with #10-24 threaded holes. Included hardware can attach to ball bases such as RAM-202U and RAM-202U-225hardware included (1) 2.1 INCHES x 2.6 INCHES Stainless Steel Backing Plate(4) #10-24 x 1 INCHES Machine Screws(4) #10 Lock Washers(4) #8-32 x 1 INCHES Machine Screws(4) #8 Lock Washersproduct dimensions 2.1 INCHES x 2.6 INCHES x .15 INCHES hole pattern 4-Hole AMPS: 1.181 INCHES x 1.496 INCHES (#8-32)1.5 INCHES x 2 INCHES (#10-24)materials Steelpackaging type Poly BagWeight 0.3 lb hardware included (1) 2.1 INCHES x 2.6 INCHES Stainless Steel Backing Plate(4) #10-24 x 1 INCHES Machine Screws(4) #10 Lock Washers(4) #8-32 x 1 INCHES Machine Screws(4) #8 Lock Washers product dimensions 2.1 INCHES x 2.6 INCHES x .15 INCHES hole pattern 4-Hole AMPS: 1.181 INCHES x 1.496 INCHES (#8-32)1.5 INCHES x 2 INCHES (#10-24) materials Steel packaging type Poly Bag Weight 0.3 lb