Upgrade Kit for cannons DEFA 552, DEFA 553 into DEFA 554: The Upgrade offers a rate of 1800 rounds/min and multi-shot in-flight re-cocking capability. This gives an increased hit-probability and enables the aircraft to remain effective even in case of ammunition problems. Take-off safety is also enhanced, as aircraft can take-off with cannons uncocked, without having to sacrifice the ability to re-cock in flight.