ID: 
482
Maker's Name: 
Siemens Halske
Dimensions: 
0.8 × 0.8 × 12.5 cm

The ceramic tube contains a series of small Selenium rectifier cells in series. This is a half-wave rectifier rated at about 15kV to 18kV and 1mA. Used in B/W TV receivers for EHT supply.