PT2605. Fast lens for Kiev (Contax) camera, released by ARSENAL in 1978-1985. Focal length - 5 cm (5.2 cm), aperture range f1.8 - f22. Focusing range from 1 m to infinity. Number of elements/groups - 6/3. Angular field - 44º. Kiev (Contax) mount. An earliest so far known lens has s/n #7800006 (Y.Davydenko coll.). Lens opposite from Ilya Stolyar (USA) collection.
PT2607. Very uncommon to find version with export markings on body. 6-digts serial number, instead of regular 7-digits one. No otherwise different from PT2605.