The CV2158 is a high power hydrogen thyratron or gas modulator for radar transmitters. The valve is equipped with flying leads that here are tucked into the base.
The serial number of this thyratron is 1416.
The braided leads in side the base.
The bayonet anode connection. The inner details are obscured.
The wide glass tube envelope is 92 mm in diameter and, including the base, is 277 mm tall.
Reference: Data-sheet. Type CV2158 was first introduced in 1955. See also1955 adverts.