The 1N4004-E3/54 is a silicon rectifier diode made by Vishay. It is designed for general-purpose rectification and can be used for circuit protection. The diode has a maximum repetitive peak reverse voltage rating of 400 Volts, and a forward continuous current rating of 1.0 Amps. It has an electrolytic resistance of 54 Ohms and a maximum power dissipation of 500 milliwatts. The diode features a double diffused junction structure and a plated axial lead. It is also RoHS compliant, making it compliant with European directives on hazardous substances.