The Olympus MMF-3 Four Thirds Lens to Micro Four Thirds Lens Mount Adapter is a dust- and splash-proof lens mount adapter. It enables you to mount any existing Four Thirds lens on a Micro Four Thirds standard-compliant digital camera, such as the Olympus OM-D Series and PEN Series models. The adapter′s weather sealing makes it preferable to the earlier MMF-2 and MMF-1 models for shooting under inclement or uncertain weather conditions. The MMF-3 is the perfect tool to help you get the most out of your weather sealed and Super High Grade Four Thirds-compliant lenses. AF shooting via Live View is enabled when using lenses that feature contrast AF compatibility. When used with lenses that are contrast AF incompatible, the AF assist function engages.