... . (3)A15, B125,C250,D400 (4)High quality. plastic manhole cover(1) Environmental protectionWith raw material non-toxicity, it ... Saving mine resourceIt is made by regenerated resin or regenerated plastic raw material, which save application of cast iron.(3) ... ear-piercing noise and shaking when car pass. Applications:(1) heavy-duty covers for motor vehicle Road, municipal pipelines, communications, power ...