This is a horizontal tank-style portable electric air compressor with pressure switch control box and a pneumatic hose. These are generally used for paint spraying or operating light pneumatic tools.
It has a vintage General Electric AC electric motor nameplate (Model 5KC45PG832KT) with key power ratings of 1 horsepower, 115/230 volts, and 1725 RPM.
Its condition is weathered with rust and paint wear on the tank and frame. Runs fine but needs oil added and a nozzle fitted to the hose. The hose functions but likely needs replaced.