This adapter converts M37 thread mount lens to common M42 thread mount.
M37 thread mount lens was used for vintage Asahiflex camera.
You can enjoy these vintage lenses by the newest camera.
The adapter does not have a flange. Infinity position depends on the lens mount and the camera mount.
If you attach into 'PENTAX Mount Adapter K', focus at infinity position will pass over infinity because Mount Adapter K is attached at the back of the camera mount surface.
First, printed adapter has joined by 'bar'. Cut the bar by nippers.
Clean up plastic powder before using: it remains in the screw part of the adapter.
By tolerance etc., you may feel tight when you attach the adapter to your lens or camera. Don't screw tight with your force. Tighten and loosen little by little, finally, you can attach!
Don't forget 'AT YOUR OWN RISK'