3", Green, Round Structural Foam Polyolefin Grate With UV Inhibitors, Open Surface Is 2.60 SQIN & It's 3.41 GPM, Fits 3" Sewer & Drain Pipe & Fittings, 3" Corrugated Pipe, & 3" Triple Wall Pipe, Recommended For Pedestrians, Bicycles, & Wheel Chair Traffic.