Fotodiox DLX Series Stretch Adapter w/Back Focus and Macro Focus Ability, Leica M Lens to Sony E-Mount Mirrorless Camera - for Sony Alpha E-mount Cameras APS-C & Full Frame i.e. NEX-7, a5100, a7R II Premium Grade Fotodiox "Pro" Adapter, Top Notch Craftsmanship Built-In Helicoid for Back Focus Adjustment and Macro Focus Ability Improved Spring Mechanism for a 'No Play' fit Infinity Focus Guaranteed 24-Month Manufacturer Warranty