Micro Switch K54133-16SW17 prototype
The photos below are archived from eBay listing 283703986380 “Vintage MICRO SWITCH prototype keypad K54133-16SW17 in original box - New” from seller robotworkshop; the original listing has since been deleted by eBay. This is a 16-key keypad with no electronic components present on the PCB (besides the Hall sensors). It is an engineering prototype of Micro Switch SW Series model K54133-16SW17, with an production date of week 50, 1976. The switches are an unidentified model and provide a cruciform slot keycap mount within extra-tall plungers. The box is pictured containing a couple of cables, neither one appearing to relate to the keypad, which expects a 32-pin header to be soldered to it, plus separate +5 V and ground wires. Each switch’s two outputs terminate separately (16 switches × dual outputs = 32 connections), while the +5 V and ground connections are shared.