Water Heater Pan 20 x 20in Square Galvanized Steel pre-drilled w side PVC slip drain adapter, 15PK This multi-purpose pan is made of heavy duty, rust-resistant galvanized steel, with a pre-drilled hole in the side to fit the included 1 inch nominal PVC slip drainhose adapter. Use for your indoor and outdoor projects in plumbing, HVAC, gardening, storage and under various appliances to prevent water or condensation leakage. The American Built Pro Pre-Drilled Square 20 x 20 inch Water Heater Pan is measured on the inside floor, with outside dimensions of 22 x 22 inch.