Perko's hardware part #0769DP0CHR is for use as a Hatch Fastener or Windshield Keeper in marine vessels. It is constructed of chrome plated brass and zinc alloy materials and it features a black polymer handle. The Hatch Fastener or Windshield Keeper has a base dimension of 1-1/2" x 5/8". The required screw size is #8 for installation.