... standard 3, With new locking system. 4, Various size. Ductile iron manhole cover1, Material :Ductile iron and grey iron, 2,Various size 3,From ... A15 to E600 Calss, Per EN124 standard, 4,With new locking system..5 ... passed ISO 9001:2000 QualitySystem,We can supply various cast iron manhole cover and water grate as your wish..