Asahi Auto-Takumar 85mm f1.8 zoom It's barely 2cm long and

It's barely 2cm long and as wide as the M mount at its widest point

and it might be worth the trouble

This Unitax right angle viewfinder is designed to fit Nikon 19mm threaded viewfinders (like those found on the FE and FM models)

it's not for full-frame cameras

Asahi Auto-Takumar 85mm f1.8 zoom It's barely 2cm long andThis is an uncommon early Asahi Auto Takumar 85mm f1. 8 lens for M42 mount, in very good cosmetic condition, with light paint and finish wear. Focusing is smooth, diaphragm is quick; the optics have only minor dust and very minor cleaning marks. Includes original case, non original front and rear caps. A lovely classic lens in pretty nice shape.