 The F-22 USV was an intermediate model, coming between the F-22, which had limited anti-aircraft capability, and the simpler and cheaper ZiS-3, which eventually replaced it in production and service.The USV had a split-trail carriage with suspension; metal wheels with rubber tires were borrowed from the ZiS-5 truck.The gun featured semi-automatic vertical sliding breech block and Bofors-type cradle; recoil mechanism consisted of hydraulic recoil buffer and hydro-pneumatic recuperator.