The ER422D-5A magnetic-latching TO-5 relay, originally conceived and developed by Teledyne, has become one of the industry standards for low-level switching from dry circuit to 1 ampere. Designed for high-density PC board mounting, its small size and low coil power dissipation make the 422 relays some of the most versatile ultraminiature relays available. The Series 422D utilize discrete diodes for coil suppression and polarity reversal protection.