Eimac VS-2 vacuum switch

As shown here, this device measures 122mm across the top and 105mm top to bottom. The glass section is approx 13mm diameter.

During WWII Eimac made the VS-1 - the VS-2 followed after the war and was one of a series of such devices produced. The range was rated at 20kV peak RF when open. In the closed position they could carry 7.5A at 15MHz, or 5A up to 30MHz. Alternatively they could switch 1.5A at 5kV DC.

Left: closeup of contacts; right: switch mounted in its solenoid ((c) Eric Tauecchio)