Nebelkerzenabwurfvorrichtung
The Nebelkerzenabwurfvorrichtung (literally “fog-candle-dropping-device,” i.e. smoke grenade dispenser, abbreviated N.K.A.V.) was a rear mounted grenade dispenser used to disperse the Schnellnebelkerze 39 smoke grenade.
Source: Wikipedia — Nebelkerzenabwurfvorrichtung (CC BY-SA 4.0)