Leica 50mm LM Ring Bright Frame 50mm/75mm Compatible Leica Mount Adapter L Mount to M Mount. This is a mount adapter that converts L mount to M mount. It is a mount adapter from the time of the Leica M2's sale, marked M2 50 M3 28-50. The bright frame supports 50mm and 75mm frames. It can be attached to cameras and lenses. Please consider this as a current condition item. Please have it serviced by the buyer if necessary. Please refrain from purchasing if you are overly concerned about condition.