3 Amp Heavy Duty Diode
Diodes are a protection device across the solenoid and in general, a one way valve for electricity.
Note the thin gray band on one end of the diode. This side with the band connects to the micro switch that turns the solenoid on and off (battery side). If it is connected backwards it will blowout the diode.
Works with 36 or 48 Volt Golf Cart Systems