Complete 'Winkelmesser 35'

Wehrmacht Gunners Quadrant for use with the 10,5cm Field Howitzer 18 (Winkelmesser 35). The tan painted metal box is nicely marked 'W.M.35' (Winkelmesser 35). Both the box and quadrant are maker marked with 'bvu' indicating production by the company of 'Franz Kuhlmann'. The set is complete with the often missing key.Nice set in good used condition!