Macro ring 25mm with signals transmission
for Canon

Macro ring is an excellent alternative for expensive macro lenses. It is mounted between camera body and lens. The ring increases distance between lens focusing surface and matrix (or film) and get larger imaging scale.

The macro ring 12mm also transmitting informations about exposure, aperture and AF between camera and lens, so it allows to use auto modes.
The ring have not any others optical elements and no affects to lens optical features.