Springfield Marine Kingpin Standard Square Base Plate With Satin Finish - 7in x 7" Stainless Steel 7in x 7in. The Base Plate dimensions are 7" x 7" with a 3" cup depth. Below the deck mount this base plate requires a 2-1/2" hole in deck. This Standard Square Base Plate can be used with Standard KingPin Posts (sold separately). Features of Springfield Marine Kingpin Standard Square Base Plate With Satin Finish - 7in x 7" Use with standard KingPin Posts (not included) Stainless steel construction with satin finish and nylon bushing Dimensions: 7" x 7"; Cup Depth: 3" Mount requires a 2-1/2" hole in deck for installation Package Contents: Springfield Marine Kingpin Standard Square Base Plate With Satin Finish - 7in x 7" Springfield Marine 1620001: Kingpin Standard Square Base Plate With Satin Finish - 7in x 7" Stainless Steel 7in x 7in