The American Built Pro Pre-Drilled Square Water Heater Pan 24 x 24 inch is measured on the inside floor, with outside dimensions of 26 x 26 inch. 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. Meets code for both gas and electric water heaters and HVAC units.• High quality, zinc-coated galvanized steel• 2” tall hemmed edges, 26 gauge galvanized steel• 1” PVC adapter included•Predrilled drain hole in the side• Will not rust or corrode• 2.5 in deep