Shortens Minimum Focusing Distance. Extension tubes are used to reduce the minimum focusing distance of the lens mounted. The Fujifilm MCEX-11 slightly to moderately decreases the focusing distance. You can check this magnification chart for a rundown of possible focusing distances.

Electronic Contacts.The built-in electronic contacts enable both autofocus and autoexposure capability, as well as transferring lens information to the embedded image EXIF data.