Features:
There is no ROM connection on the ring so diaphragm control of the lens is set manually, For Canon cameras (A-1, AE-1 Program, F-1, FTb and others) with M42 lenses (for Praktica, for Zenit). M42 lenses are not interchangeable with FD optics, as they have different flange bases. This difference is compensated by the thickness of the adapter, and this fact make M42 lenses work with FD cameras in usual manner.
Please installing / uninstalling the adapter after turning off the camera:
Put the red marks on outer and inner rings of the adapter with red mark on the lens collar together.
Turn the outer ring clockwise till the end.
Screw M42 lens on the adapter.
Removing of the adapter is made in inverse.
It is possible to use macro rings and other accessories.
It can focus to infinity.

Specifications:
Material: Aluminium
Color: Black and Silver
Lens: M42 mount lenses (for Zeiss, for Pentax, for Praktica, for Mamiya, for Zenit)
Camera: for Canon FD mount cameras

Package includes:
1 x Lens mount adapter