A unit is a Good Services of 
1)Ship renewal and repair works - Indian navy Ships and Cargo ships-Repair and renewal of hull works (ship steel repair), air pressure testing of ship underwater tanks and clusters, repair and renewal of deck machinery, overhauling / maintenance of marine diesel engines, repair and overhauling of pumps and motors, supply of marine items and goods (bearings ,fasteners, mechanical seals, wing nuts and gaskets)