VILTROX EF-EOS M2 mount adapter is designed to allow Canon EF-mount series lenses to be used on interchangeable-lens digital cameras that compatible with EF-M lens. | Focal length is multiplied by 0.71 based on the original (equivalent focal length =focal length x 0.71), which helps enlarge 1 level aperture. | With auto focusing function - Can increase the lens 3 f-stop, increasing the amount of light into the virtual background,can better highlight the theme | It is also built in 4 groups,4pcs optical glasses. it can achieve functions of EXIF signal transmission, AF(autofocus) and adjustable aperture,etc. | Equipped with USB interface, can realize software upgrade. Can perfect new functions of the lens mount adapter and fix bugs according to follow-up upgrades.