Panzer II variants the Pz.Kpfw. IIJ, it was redesigned after the Panzer V Panther, most noticeably with the introduction of fully sloped frontal armor. Two versions were initially planned, a lighter, faster 18-ton variant and a slower, 26-ton vehicle; the former was abandoned at an early stage. Subsequently, work on the first prototype was abandoned when it was determined that the vehicle was underarmed for its weight, and versions of the Panzer IV and V could serve just as well in the reconnaissance role while being more capable of defending themselves. This vehicle never received an official Panzerkampfwagen title, but it would have
QF 4-inch naval gun Mk V and W class destroyers of 1917 also mounted the gun. Mk V was superseded by the QF 4 inch Mk XVI as the HA (i.e. anti-aircraft) gun on new warships in the 1930s, but it continued to serve on many ships such as destroyers, light and heavy cruisers in World War II. Early in World War I several guns were supplied by the Navy for evaluation as anti-aircraft guns for the home defence of key installations in Britain. They were mounted on static platforms and proved fairly successful after a fixed round was developed to replace the original separate round,