KingPin(TM) 7" x 7" Stainless Steel Square Base (Threaded)KingPin(TM) 7" L x 7" W Satin Stainless Steel Threaded Square Base with Nylon Bushing for 1-3/4" D Post (1630001) by Springfield Marine. Springfield Marine knows that comfort is important in marine seating. Whether behind the wheel for long passages in rough water; dropping a line in a quiet creek; or anywhere in between, Springfield Marine offers a wide range of configurations and options.Features: 7" x 7" stainless steel base, with nylon bushing and satin finish 4" cup depth below the deck Mount requires a 2-1/2" hole in the deck Built to provide secure, hassle-free boat seat mounting Specifications: Post Diameter: 1-3/4" Length: 7" Width: 7" Finish: Satin Material: Stainless Steel WARNING: This product can expose you to chemicals which are known to the State of California to cause cancer, birth defects or other reproductive harm. For more information go to P65Warnings.ca.gov.