The first two vessels were built by HDW at Kiel, while the remainder were built at Mazagon Dock Limited (MDL), Mumbai under a technology transfer agreement. The ships were commissioned between 1986 and 1994.
These submarines have a displacement of 1660 tons when surfaced, a speed of 22 knots (41 km/h), and a complement of 40 including eight officers.
India signed the agreement for these submarines with HDW in 1981. The initial agreement called for delivery of four submarines which were delivered to the Indian Navy between 1986 and 1994. A subsequent agreement for the construction of 2 more submarines to be constructed at MDL was cancelled after the Pokhran-II nuclear tests in 1998.