The 20mm Polsten was a design developed by Polish and British designers, and allowed for an effective automatic cannon at less cost and quicker manufacture than the far more complex Oerlikon cannon.
The Polstens were used by Allied forces in both towed mounts as well as on vehicles and AFVs (e.g. LVTs)
This model is meant to be printed in FDM as fine settings, with supports. please test fit before gluing. The turret basket is free fitting but the gun pack must be glued in.