PT8205. Seems to be an earliest version of "Jupiter-11" lens. Under initial name "ZK-135" ("Sonnar Kransogorsk"). Very few lenses released by KMZ in 1948-1949. These first samples are totally assembled from Zeiss (Germany) optical glasses. Focal length - 13.5 cm, aperture range f4 - f22. Focusing range from 2.5 m to infinity. Number of elements/groups: 4/3.  Angular field - 18º. Zorki (M39) mount. An earliest so far known lens has s/n #000022 1948 (source: J.L.Princelle).

Lens #000024 opposite from private collection in Russia.

PT8205 - ZK 4/135 mm  #000024 (1948).

PT8210. Almost identical to its predecessor "ZK-135", but under name "ZK Zorki" already. Very limited batch of these lenses released by KMZ in 1949-1951. Partially or totally assembled from Zeiss (Germany) optical glasses. An earliest so far known lens has s/n #4901389 (A.Nikitin coll.).

PT8215. Lens almost identical to PT8210, but under regular name "Jupiter-11" already (see comparison picture above). Released by KMZ in 1950-1959.  Some lenses have an additional enagravings "MADE IN USSR" on body. An earliest so far known lens has s/n #5000952 (D.Cichetti coll.). Lens PT8215 above has s/n #5502614.

PT8210 - ZK Zorki  #5101182.

PT8220. Almost identical to PT8215, but released by KOMZ ("Kazansky Optiko-Mechanichesky Zavod") in 1957-1961. Quite common to find nowadays.

PT8225. Almost identical to PT8220, but with new markings on the lens faceplate already: markings "1:4  F=13.5 cm" replaced by "4/135". "Jupiter-11" markings in Cyrillic characters. Released by KOMZ since 1961.  

PT8220 - Jupiter-11  #5805922.

PT8230. Almost identical to PT8225, but with black anodized finish. Released by KOMZ since 1968. Different engravings "MADE IN USSR" on body are known to exist (see picture below). Name markings in Cyrillic characters. Less common to find nowadays. 

Lens opposite from private collection in Europe.

PT8230 - Jupiter-11 lens (KOMZ).