Perko Chrome Clam Shell Ventilator Perko clam shell ventilators are ideal for many applications, from covering vent holes for battery boxes, water tanks, and fuel tanks to venting engine compartments. Made of chrome plated brass. Each is pre-drilled for installation screws not included. Specifications 0315DP1STS Base Dimensions 1-58 x 1-12 Opening Height 716 Opening Width 78 Screw size 4 California Residents WARNING Cancer and Reproductive Harm - P65Warnings.ca.gov Other Details Google Product T