Our Products AluminumAluminum Valve Boxes, Extension & RisersAluminum Rectangular Frames, Grates & CoverAluminum Meter Pit CoversAluminum Manhole Ring & Covers, Extension Rings, & Frost Proof CoversAluminum Inverted Manhole Ring & CoversCast IronCast Iron Valve Boxes, Roadway Boxes, Curb Boxes, Triangle Boxes, & Clean OutsCast Iron Meter Pit Covers, Top Lids, ExtensionsCast Iron Manhole Ring & Covers, Frost Proof Covers, & Extension RingsCast Iron Inverted Manhole Ring & CoversCast Iron Inlet Frames & Grates, Tree GratesDuctile IronDuctile Iron Manhole CoversSteelSteel Inlet GratesPlasticPlastic Inner Lids & Meter Cover Top Lids Search Submit Clear M18CI & M21CI OVERVIEWMaterial: Cast Iron Description: Water Meter Pit Ring & Cover Model #: M18CI & M21CI Specifications Approximate Weight COVER12# RING18-21#M 20-25#, M 21-30# NOTES: Available with hole in center knock out style M18M21 A - 17 3/8" | B - 20"A - 191/2" | B - 22" M21A 20 1/2" | B - 23" Product Details