| Year | April 1941 |
| Weapon Type | Heavy Anti-Aircraft Gun |
| Origin & Designer | Germany/Rheinmetall |
| Numbers Produced | 450 |
| Crew | 10 |
| Calibre | 128mm (128x958) |
| Elevation | -3° to +88° |
| Traverse | 360° |
| Breech | Horizontal Sliding Block |
| Recoil | Hydropneumatic |
| Gun Sight | [@gun_sight] |
| Gun Mount | Pedestal Mount |
| Carriage | 2 x Four Wheeled Carriages |
| Trailers | [@trailers] |
| Gun Shield | [@gun_shield] |
| Armoured Plate | [@armoured_plate] |
| Barrel Length | 7.836mm (L/61) |
| Overall Length | 15m |
| Width | 2.50m |
| Height | 3.96m |
| Weight | Weight in Traction: 27.034 kg Weight in Action: 13.000 kg |
| Round Weight | 27.9 kg |
| Muzzle Velocity | 880 m/s |
| Feed | [@feed] |
| Magazine Capacity | [@magazine_capacity] |
| Practical Rate of Fire | 8 r.p.m. |
| Rate of Fire | [@rate_of_fire] |
| Maximum Rate of Fire | 12 r.p.m. |
| Maximum Ceiling | 14.800m |
| Maximum Ground Range | 20.475m |
| Maximum Range | [@maximum_range] |
| Armour Penetration | 143mm @ 1000m @ 30° |
| Traction | Motorised (Two Loads) |
| Variants | [@variants] |
| Notes | The Flak 40 was a heavy anti-aircraft gun which was used as a static gun to defend key locations and cities. It was difficult to transport and many were transported by rail and mounted on flatcars. It was a success and classed as one of the best heavy anti-aircraft guns ever produced. |