Tomioka Beauty… rather rare lens in this apparently near mint condition. If we understand the serial numbering system… the ‘552’ is the model number if you will (for lack of a better term). The 55 = 55 mm and the ‘2’ is the maximum aperture of 1.2. The next numbers are the production sequence numbers… 1,773 rd made.
So there you have it! One of the best of the original super fast 55 mm lenses for the M42 mount.