Genuine Siemens Munich tube from 60´s

1 Siemens tube E188CC /7308 =  E88CC 6922 CC

A frame getter tube

Tubes with  factory code (inside metall tag) : "G6 2L"

Test result S/gm very high : 

12,2 + 12,5 mA/V 

with Burn-In in special device