The CV2430 is an S-Band TR cell designed to protect the front-end of radar receivers during the transmit pulse. This exhibit is designed to plug to waveguide WG10. The maximum peek power it is designed to operate within is 10 kW..
The gap between the electrodes will ionise in the presence of a large RF field and thus close off the receive port. The gas filling is probably low pressure water vapour.
This small TR cell came in a much larger aluminium can and was wrapped in a polythene bag with foam within. The can measures 63 mm in diameter and is 236 mm tall. The can was to be filled with desiccant to keep the cell dry in storage.
The thin glass tube envelope is 15 mm in diameter and, including the base, is 130 mm tall.