This is a single station level switch, made by Imo Delaval, Inc, Gems Sensors Division, in Plainville, CT.
It is a Gems Series LS-3 Level Switch, Pilot Duty, 10VA, 50 to 240 VAC. Part Number 42295.
It comes to you in very good pre-owned condition, unused, in its original box, with installation and instruction manual. The box has been opened, and is scuffed up from being stored and handled.