An accessory ring which converts
the lens mount of your SLR camera to a T-Mount. The compatible Opteka T-Mount
System makes it possible to use most any single lens reflex camera in
combination with various front camera attachments such as telescopes, mirror
lenses, slide duplicators...etc. The T-Mount is a metal connector that screws
onto the compatible front attachment and allows this combination to be coupled
to your SLR camera lens mount.