... A15,B125,C250,D40 FRP,GRP, SMC , DMC,BMC Manhole covers, gratings,gully tops and Tress grilles, and etc, Which are made from ... advantages:1.Anti-theft, the materials FRP/GRP ,SMC, DMC/BMC are not be used again.2.Anti-corrosion, the materials ... FRP/GRP ,SMC, DMC/BMC have high anti-corrosion.3. Long use-age life (Not ...