The SAAB 21 is a Swedish single-seat low-wing monoplane fighter and attack aircraft.
The first example from the first batch of 54 of the first production variant, the J 21A-1 was delivered to the Swedish Air Force on 1 December 1945.
However, within less than four years, some squadrons were already being re-equipped with a new generation of jet fighters capable of far greater speed, such as the de Havilland Vampire.
Despite the original intention for the type to be principally in air defence roles, in service, the J 21 was utilized mainly in the light bomber role. The type was used only by the Swedish Air Force.
https://en.wikipedia.org/wiki/SAAB_21