Supply of Sealing Ring For Manhole Cover. Drawing No: W / Tf - 2169, Alt. 1. Spec. No. :Irs Specifi Cation No. R-3-70 With Corrigendum No. 1 To 4 Warranty Period: 30 Months After The Date Of Delive Ry Quantity Tolerance +/-: 5 %Age, Item Category : Normal, Total Po Value Variation Permitt Ed: Max 8 Lacs