Bild API Two-Piece Drop Adapter with Sight Glass Markets Petroleum Cargo Tanks Jump to Section Product Options Related Products Product Options Part Number Size Seal Material 4501ASSM 3" Baylast™ O-ring Aluminum 4502ASSM 4" Baylast™ O-ring Aluminum Related Products Bild 6200-Series Side-Lever Type Drop Elbow Bild API Drop Adapter Bild API Drop Adapter Repair Kits Bild API Drop Adapter with Sight Glass Bild API Load Only Valve Bild API Load/Unload Valve Bild API Two Piece Drop Coupler with Sight Glass