The 4" QF gun served on a wide variety of Royal Navy vessels during World War Two. This High Angle (HA) Dual purpose (DP) gun and mount was refit to many ships over the course of World War Two to correct the shortcomings of the 4.7" SP gun. The Mk XVI was a popular weapon, and production could not meet demand until late in the war. This weapon was found on most RN capitol ships and cruisers, and many destroyers and smaller ships.

This set of 4" guns (the box art lists the wrong gun) from Flyhawk is comprised of 4 gunhouses and 4 twin breeches made from fine white resin, 8 machined brass barrels and a fret of photoetched details, and packaged in a unique plastic clamshell box. The single sheet of instructions is comprehensive; the builder can choose between open and closed ports in the shield for the gunlayer.