New-Old-Stock (NOS) tube.

The 26Z5W is a ruggedized heater-cathode type double diode using the 9 pin miniature construction. It is suitable for use in half or full wave rectifier applications or as a voltage doubler. The heater design makes this type ideal for operation in airborne equipment where a 26 volt power supply is normally available. Also the ruggedized structure is capable of withstanding severe shock and vibration such as that encountered in aircraft.