This interesting item is a high vacuum RF relay with two changeover poles.
The actuator is in the base and the central rod rotates.
The two pin base with the operating voltage printed on it.
Top view showing the arrangements of the contacts.
The contacts have rounded ends and the switch element is a flat paddle. The central tube is an insulator as the device is designed for high voltage.
Another view of the switch contacts.
The data sheet.
The wide glass tube envelope is 26 mm in diameter and, excluding the base pins, is 75 mm tall.
Updated August 30, 2022.