Cast Iron Manhole Cover Manhole cover: composite materials, artistic, theftproof. long working life, abrasion resistance Cast Iron Manhole CoverTheftproof artistic manhole coverROUND TYPECover size:diameter 500mm, 600mm, 700mm , 750mm.Load ability: A15, B125, C250 ,D400artistic, theftproof long working life, abrasion resistance etc.