Tree Root Barrier,Tree Root Guard,Tree grate Meterial:Made of ductile Iron Outer diameter:1000mm ... Inner diameter:500m Tree Root Protection,Tree Grate,Tree Guard,Tree Root Guard for tree protection.Tree Root BarrierMaterial:Made of Ductile ... :1/2,1/4Finsih:Black forge colour painted Tree Root Barrier,Tree Grate,Tree Guard