The adapter is secured by 1 set screw (installed) with an allen key (included)

This adapter can be used to install Kiev-16U lenses (16mm movie film format) onto cameras with M32X0.5 Female thread. 

The adapter is for Canon EF-M mount cameras. Infinity focus is preserved.

Female thread is M32x0.5mm.

Please note that sensor of Canon EOS M camera is larger than 16mm film camera frame. So, Kiev-16U lenses will vignette. Shown picture was took with 50mm lens. Wider lenses will vignette more.

Material for metal,reliable performance.Durable.

More information for your reference:

The Kiev-16U lenses consist of; 

MIR11-M: 12/2 (IC 12.3mm) 

VEGA7-1: 20/2 (IC 14.07mm) 

TAIR-41M: 50/2 (I don't know the IC, but it should be larger than the 20/2's) 

The Image Circle (IC); 16mm IC 12.7, Super16mm IC 14.55mm 

These lenses are really small in size, and could prove perfect companion for the Pocket Camera.