QF Mark II was a single gun mounting (Mounting Mk 1) anti-aircraft gun in static sites. The pedestal mount was bolted to concrete in an unarmoured turret, a travelling platform was available to transport the gun and mounting between positions. The first unit became operational in February 1939. These 16.5 ton anti-aircraft mountings had a maximum elevation angle of 80 degrees. However, most mountings were Mark 1A with an elevation range of -9.5 to 80 degrees. This enabled the gun to be dual role (anti-aircraft and coastal defence) in coastal areas. Armour piercing rounds were provided for anti-ship engagements.