The country patented product---high polymer mould pressing manhole covers and grating that the company produces, Adopt material such as BMC resin and fiberglass, The inner attaches a steel skeleton, this product has density height, hardness height, intensity of pressure height, weight merit such as light, resistant to corrosion, resisting to age after high-handed mould pressing molding of high temperature. By that the country authority branch checks, bear weight reaching more than fifty tons, the various index exceeds a national standard without exception, is to exceed other in the homeland compound material manhole covers more. Be put into use be suitable to the municipal engineering, the fast traffic lane most, the product is sold to the whole world everywhere, Can not produce waste gas, waste water et cetra and in procedure of production, be unable to bring about to the environment contaminating. Be the idealest ductile iron manhole covers succedaneum, and be able to substitute ductile iron well cover gradually!