Seller's description: A cabinet card showing an odd mechanical device of undetermined purpose. The words ‘Belegt’ and ‘Frei’ above and below the knobs numbered 1 to 4 translate as ‘Occupied’ and ‘Free’. An engraved metal plate near the foot of the device identifies the Gustav Binter Company of Munich, who are further identified by a wetstamp on the reverse of the mount as a ‘mechanische Werkstätte’ [mechanical workshop]. Below this there’s a patent number.