This is a mystery. It was made by Lorenz in Germany and the plastic knob suggests a military valve designed for rapid replacement in the field. Visually this looks like an indirectly heated diode with short leads to the pins that are recessed into the glass bulb.
A design like this suggests a detector for UHF or possibly radar pulses.
Comparing the knob dimensions with other easy replaceable valves indicates thet the envelope is 40 mm in diameter - the same as other valves of the time.
In this image the white insulation on the heater can be seen as it enters the caathode tube.
The Lorenz name on the special five pin base.
Thanks to Oлer for sending these pictures.
The wide glass tube envelope is 40 mm in diameter, and excluding the base pins is 40 mm tall.
Updated February 23, 2017.