The ER411D-5A 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 specifically for high-density PC board mounting, its small size and low coil power dissipation make the 411 relay one of the most versatile ultraminiature relays available. The Series 411D relays have internal discrete silicon diodes for coil suppression and polarity reversal protection.