RE: E-75
Hi Philipat
KWK = KampfwagenKanone (Fighting Vehicle Cannon/Gun)
The length is measured in multiples of the calbre, so a 75 mm kwk 42/L70 = 75mm X 70 = 5250mm or 5.250 metres
The 88mm kwk 43 / L71 - 88 mm X 71 = 6248mm or 6.248 metres
Hope this helps
Mal