Z100-2NH - 15" Diameter Cast Iron Roof Drain, 2" Pipe Size - Body OnlyThe Zurn Z100 15" diameter roof drain has a Dura Coated cast iron body with combination membrane flashing clamp gravel guard and low silhouette Poly Dome. Features 15" diameter primary roof drain Clamping collar and low silhouette Poly Dome Dura Coated Cast Iron Body with Combination membrane and flashing clamp gravel guard Engineering Specifications 15" [381mm] Diameter roof drain. Dura Coated cast iron body with combination membrane flashing clamp