Poly Dome: Outside diameter 12-1/2" Cast Iron Dome: Outside diameter 12-1/2" Clamping Ring: Outside diameter 13-1/2" Deck Plate: No underdeck clamp is required Bolt-to-Bolt: 180°:9-1/2" Serves purpose of roof sump receiver Can be pre-assembled to drain body, great for pre-fab applications It’s Fast – Contractor can install roof drain in half the time as conventional methods … a superior method of installation using a bolt-down system that secures roof drain assembly...