Bild API Drop Adapter with Sight Glass Markets Petroleum Cargo Tanks Jump to Section Product Options Related Products Product Options Part Number Size Seal Material 4530SG 3" Baylast™ flat gasket Aluminum 4540SG 4" Baylast™ flat gasket Aluminum Related Products Bild 6200-Series Side-Lever Type Drop Elbow Bild API Drop Adapter Bild API Drop Adapter Repair Kits Bild API Load Only Valve Bild API Load/Unload Valve Bild Gravity Drop Adapter Dust Cap