This is a brand new 50 amp potential relay.  This relay is used with single phase motors that use start and run capacitors and other "high starting torque" motors.  Typical use include air conditioning and refrigeration compressors, heat pumps, and submersible pumps.  These relays are routinely used in well pump control boxes like Franklin control boxes 5 to 15hp, 230 volts and others.  These are easy to replace and typically go bad when the system is struck by lightning, or cycling off and on excessively

Don't buy a whole new control box, replace the relay.