This is a German magnetic Anti-Tank mine 'Haft-Hohlladung 3kg' used by tank killer squads in built up areas. It was a hollow charge which was secured on the target by three very strong magnets. Once the friction igniter was pulled, the charge had a delay of approx 5 - 8 seconds.
Weight - 3.49 kg
Weight of charge (TNT) - 0.98 kg
Diameter of charge - 108mm
Height of charge container - 197mm
Height of magnets - 70mm