... inspect result is 54 tons, accord with Construction Department of Peoples Republic of China CJ/T211-2005 Criterion.2. Beautiful ShowManhole cover ... beautify the environment.3. Light WeightIt weight only 1/3 of cast-iron manhole cover, more expediently transport, install, and rush to ... between cover and its under. It gets over the problem of cast-iron and cement manhole cover run, jump, sound. It ...