Tube come in original box (too big to photo with tube)

Gas-discharge cathode-ray tube for demonstrating the properties of electron beams.

Most photos made with handheld Tesla coil, other (as it should work with heating - from internet)

The flask contains by some sources a hydrogen generator and an electron gun.

As for for me - gas spectre is most like Krypton gas - its blue, maybe its different modifications, tell if you know please.

Manufactured by JSC Electronic Devices, Ryazan, 1990 (ex-USSR)