... ,high strength Plastic sewer coverproductmodelcolorclassmaterialproduct charactersewer coverround 500mmanyA15, B125,C250,D400composite resin,fiberglass,fabric1.High strength: composite resin,fiberglass ... ,so strength is high.2.Light weight: the composite manhole cover is lighter than iron manhole cover3.Nice ... cover,so it will keep long.4.Safty: composite resin as raw material,non-toxic,do harmless to ...