Despite the name, this version of the 55/1.8 had build in full auto-aperture, just like the later Super Takumars. It differs from the previous Auto Takumar 55/1.8, produced in 1958, only by the mount and the aperture mechanism. This version was discontinued in 1962.

Takumar 55mm f/1.8 versions summary:
Asahi Optical Co. Takumar 55mm f/1.8-22
Asahi Optical Co. Auto-Takumar 55mm f/1.8-22
Asahi Optical Co. Auto-Takumar 55mm f/1.8-16
Asahi Optical Co. Super-Takumar 55mm f/1.8-16
Asahi Optical Co. Super-Multi-Coated Takumar 55mm f/1.8-16
Asahi Optical Co. SMC Takumar 55mm f/1.8-16