1.Standard:ISO9001:2008 ,EN124 2.Size:250mm~1200mm 3.Loading abality:A15,B152,C250,D400 4.Design:as customer's requirement. Zibo Best Energy-saving Materials Co., Ltd was established in 2004, which is one of the largest composite manhole cover manufacturer in China, specializing in producing and supplying composite materials(FRP/GRP) manhole cover, rain-grating ,tree-grating, flower pot, fence ...