The 6E1P is a Russian tuning indicator similar to the EM80. In Cyrillic the Type designation is 6E1П. The design use is as a guide to the correct tuning of a radio broadcast.
The lettering gives the country CCCP and the OTK code indicates a a Army quality stamp.
The electrodes are horizontal and a fan display is projected upwards. The shadow closes as the signal peaks.
The thin glass tube envelope is 22 mm in diameter and, excluding the B9A base pins, is 64 mm tall.
Reference: Data-sheet. Type 6E1P was first introduced in 1958. See also1958 adverts.