An unusual one I think that might be of interest....
On the filter ring it's identified as a ГEЛИОC-44М 2/58 with the brand symbol for Lomo.
Seller's auction statement:
I bring to your attention rarity USSR Russian black photographic collectables lens Helios-44M f2/58mm with a spring-elastic diaphragm, M42 groove to Zenit-EM, Zenit-TTL, Zenit-12sd, Zenit-12xp, Zenit-122, Zenit-11, Zenit-ET, Praktica etc, LOMO, Leningrad (St-Peterburg). All features have been tested and work properly. Glass on lenses is clean, no fungus. Lens is in condition good, only for a long time laid in a stock! This lens is a stylish acquisition for collectors, good present or for everyday use!
S/n: 8207656
* Diaphragm: 2/2.8/4/5.6/8/11/16
* Focusing, m: 0.55 to 10 and infinite
This lens does have a full-auto diaphragm with the Practica-Pentax push-pin actuation, and an auto/manual pivoting switch for checking depth of field. There are 6 elements in four groups, nearly symmetrical. It's a copy of the pre-war Zeiss Jena Biotar, an early forerunner of the Planar I think. Lenses later than this with naming such as Helios-44M4 and 44M6 have an area opposite the diaphragm pin cut away for the movement of an internal peg that probably keys the set aperture to the camera body, but those lenses do not have the lens-mounted auto-manual switch. An earlier model without the M (Helios-44) has a manually pre-set diaphragm stop-down. It carries the cemented-pair logo of MMZ (Minsk Mekanicheskiy Zavod?), a factory subsidiary to GOMZ (LOMO after 1962) in Leningrad, and which in 1971 became BelOMO (Belarus Optiko-Mechanicheshkoye Obyedinenie, or Belerussian Optical-Mechanical Union) and subsidiary to KMZ (Krasnogorskiy Mekanicheskiy Zavod).