BGM-71C ITOW reached IOC (Initial Operational Capability) in April 1981. It had a new copper lined warhead of slightly larger diameter, and also an extendable nose probe fuze. The probe extended after missile launch, and ensured that the warhead detonated at a stand-off distance from the target for optimum efficiency of the shaped charge. The new warhead and fuze improve the armour penetrating capability to about 700 mm. The BTM-71C is the corresponding training round.