This is an injection-plastic jet aircraft model kit.
From the manufacturer:
The B.(i)6 variant of th Canberra was an interim development, designed to fill a gap in capability until the improved B.(i)8 was introduced. Featuring a removable ventral gun pack consistingh of 4 20mm cannons, the B.(i)6 was a powerful strike machine. With additional underwing hard points and the capability to carry tactical nuclear weapons, these aircraft performed well intheir time in RAF service. The B.20 was essentially a B.2, with additional tanks in the wing and built under license in Australia.
41.6cm long and 40.6cm wide when assembled, with 182 pieces. Includes decals for two marking variants.