... ,save resources 3.Light weight,20 year's history fiber glass manhole cover,EN124 1. High strength:its strength is ten times as ... level of ordinary steel;2.Corrosion-resistant:it stainless, no mold, no rot, no paint, the ability of many gas, corrosive liquid medium ... its long life, and can be used two decades, and no maintenance, thus The overall economic efficiency is much better than ...