The L102/2K is a Barretter or current stabiliser. In fact this is a dual stabiliser with independent filaments.
It is designed to work with a voltage drop of 85 Volts and this is achieved with a current of 120 mA. These stabilisers are based on non linear ristances in this case at 40 mA the drop is 5 Volts, at 70 mA the drop is 20 Volts.
The wires on their supports.
The wire appears solid but close-up it can be seen to be tightly wound coil.
The thin glass tube envelope is 20 mm in diameter, and excluding the B9a base pins is 46 mm tall.