A wall-mounted industrial electrical isolator switch made by MEM (Midland Electric Manufacturing). Used to turn power on/off to a machine or workshop circuit. The side lever physically engages/disengages internal contacts — very robust mechanical design. Would have used in machine shops, textile mills, engineering workshops, factories, schools/technical colleges, large garages.
Sunburst/Art-Deco style front casting 1930s-1950s.
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