LSP T-0054 Plastic Roof Drain with 4-Inch Side Outlet 4 inch roof drain is constructed of durable ABS plastic which is resistant to corrosion Combines roof drain, flashing skirt and overflow all in one unit Drain/Flange: 24 in. x 18 in. Drain Basin: 10 in. High Impact Compounds provide a tough, durable product able to withstand construction site handling