Sewer Grate 4 3D model is available on CGTrader for $2. Original author: js3dcreative. Specs: 6 polys, 8 verts.
MAX (Autodesk 3ds Max, filesize: 3.84 MB), OBJ (OBJ, filesize: 1.71 KB), FBX (Autodesk FBX, filesize: 86.9 KB), DXF (DXF, filesize: 57.4 KB), 3DS (3D Studio, filesize: 1.39 KB), DWG (AutoCAD, filesize: 24.3 KB)