Carl Zeiss Flektogon copy!

The Mir-1B 37 mm f/ 2.8 m42 is an interchangeable wide-angle fast coated lens. It is equipped with an iris aperture with preset mechanism. In 1958 it was rewarded the Grand Prix at the Expo-58 in Brussels. In 1959 the lens was rewarded  the 2nd degree diploma of the Exhibition of Achievements of the National Economy of the USSR. The optical scheme of the Mir-1 37 mm f/ 2.8 was designed by S. Volosov in 1954 and was based on the Carl Zeiss Jena Flektogon 35mmf/2.8, manufactured after the WW II by the Carl Zeiss, Jenna. It has a negative meniscus as the front lens, which considerably reduces vignetting when wide open.
The Mir-1 37 mm f/ 2.8 was produced at different times by the KMZ, the Zagorsky Optical and Mechanical Plant (ZOMZ), the Vologda Optical-and-Mechanical Plant (VOMZ), the Arsenal Factory.It was recommended for all types of photography. It was considered especially useful when extraordinary sharpness of all details of the image was required. The lens really produces a rather sharp picture, while "voluminosity" is well retained. Many photographers consider the Brusseles Grand Prix inscription to have better characteristics.
The lens is done very well. Blackening, including that of aperture blades, is of good quality. With a special adapter can be attached to modern dSLR and mirrorless cameras. It's easy to use on Pentax (bayonet K) cameras using a simple metalic adapter saving focusing on infinity. The resolution according to the technical specifications (center/edge):  45/23 lp/mm Aperture control is manual with aperture ring with a pre-adjustment function. Many photographers consider the 1st version of the Mir-1 with the m39 screw mount and the Grand Prix Brussels inscription to have better characteristics. That accounts for the fact that the quality control of the 1950s and early 60s was more serious than in the following years when volume of production  greatly increased.