The 12.8 cm Selbstfahrlafette L/61 (12.8cm L/61 Self-propelled Mounting) or Panzerselbstlafette V (Armoured Self-propelled Mounting Mark 5) was armed with a huge Rheinmetall 12.8 cm gun based on the gigantic 12.8 cm FlaK 40. With such cumbersome designations, it quickly gained the unofficial nickname of ‘Sturer Emil’ (Stubborn Emil). The two vehicles were named Max and Moritz after the naughty boys in Busch’s famous German children’s tale.