While these six aircraft provided a limited tanker capability suitable for refuelling fighters, the Mk 20A wing hosereels could only deliver fuel at a limited rate, and were not suitable for refuelling bombers. Work therefore continued to produce a definitive three-point tanker conversion of the Victor Mk.1. Fourteen further B.1A and 11 B.1 were fitted with two permanently fitted fuel tanks in the bomb bay, and a high-capacity Mk 17 centreline hose dispenser unit with three times the fuel flow rate as the wing reels, and were designated "K.1A" and "K.1" respectively.