Amarine-made Stainless Steel Clamshell Vent/Wire Cover Clam Shell Vent for Boat - 07725S Clam shell vents 16mm (H) x 54mm (W) x 57mm (L), th=0.6mm Stailess steel Amarine-made A = 5/8" B = 2-1/4" C = 2-1/8"