There are two versions of this Cosina made lens. They are identical optically but there are some differences in mechanical part, especially for infinity focus adjustment. Earlier version with metal focusing ring (v4a)has adjustable focusing ring stopper plate. Rubber grip version (v4b)has no ability to adjust infinity, there is a metal spacer ring between optical assembly and helicoid assembly and the only way to adjust infinity is to change spacer thickness.

This lens also known as:
Cosina Cosinon Auto 55mm f/1.4-16 (v1)
Carenar Super Carenar 55mm f/1.4-16
Vivitar VMC Auto 55mm f/1.4-16
Revuenon Auto Revuenon 55mm f/1.4-16 (v4a)
Reflecta Super Reflecta 55mm f/1.4-16