Spring For Am-12 Pantograph To Sil Old Part No Sooo301/Sil New Part No S0221125901 Or To Contransys Part No Co15660 Or To General Stores And Engineering Co Drg. No. Gsec/Panto/061 , With Stiffness 0.5 +/-5% Kg/Mm As Per Rdso Modification Sheet No Elrs/Ms/0333 Rev-O. [ Warrant Y Period: 30 Months After The Date Of Delivery ] ]