Y shaped Lens Support Plate provides physical support for wide-angle and especially long telephoto lenses, thus relieving the potentially damaging pressure on the camera's lens mount.
Makes M42 mount lenses (for Zeiss, Pentax, Praktica, Mamiya, Zenit) can be used for Canon EOS cameras, such as 5D, 5D2, 5D3, 7D, 60D, 450D, 550D, 600D, 750D, 760D and so on.