This page shows the Russian V1V (Cyrillic B1B) SPST vacuum relay. To purchase these relays,
The contacts are rated for 3KV, 10A up to 30MHz.
With coil voltage between 24.3 and 29.7VDC, switching time is no more than 20mSec.
The relay will pull in at 18VDC, and drop out at 4VDC.
Coil insulation is more than 50 megohms.