This is the SIGMA Mount Converter MC-21 EF-L, which allows you to use EF-mount lenses on L-mount bodies. The rear cap has some scratches, but the rest of the adapter is in good condition (see photos). I have confirmed its operation with SIGMA EF-mount lenses on a LUMIX S1H (including AF and aperture control). It will be shipped in its original box. Thank you for your consideration.