This series of 500 watt voidless hermetically sealed unidirectional Transient Voltage Suppressors (TVS) are military qualified to MIL-PRF-19500/551 and are ideal for high-reliability applications where a failure cannot be tolerated. Working peak "Standoff" voltages are available from 5.0 to 51.6 volts. They are very robust, using a hard glass casing and internal Category 1 metallurgical bonds. These devices are also available in a surface mount MELF package configuration.