Technical characteristics si21bg si22bg : 

Working Voltage - 350V-450V.
Registration range  1000R\hour
Plateau slope - not more than 0.15%\V.

Plateau Lenth 100V

Background - not more than 1.3 pulse/sec.

Load resistance - 5.1Ohm.
Input capacity - 10pF.

The ambient temperature - from -40 ° C to +50 ° C.
Direction of polarity - must be in two opposite directions.

Dimensions:
Total length  - 70mm;
Working active length - 60mm;
Outer diameter - 10mm;
Weight - 8g.

I ship with a tracking number by air mail, all my items are always packed well.