Asahi M42 Extension Tube Set brand_MIOM and manual focusing action is

and manual focusing action is old-school smooth

Mamiya Auto-Ext Ring Set is a complete set of three manual focus extension tubes for the Mamiya 645 camera

The Leitz Macro-Elmarit-R 60mm f2

but be careful

Asahi M42 Extension Tube Set brand_MIOM and manual focusing action isThis Asahi extension tube set includes three M42 thread mount extension tubes: roughly 9mm, 19mm, and 29mm, for a total of about 57mm extension when combined. These are manual diaphragm tubes without autodiaphragm passthrough. In excellent condiiton overall, with minor paint and finish wear. Includes original box, which is lined with purple flocking and white satin, and rules.