Auto Extension Tube Set for Nikon Z MountDescription Overview Kenko Extension Tubes are an attractive way to convert your standard lens into a macro lens. Kenko Extension Tubes are void of optics. Their purpose is to move the lens farther from the the image sensor. The further the distance the bigger the magnification becomes. Macro lenses are usually more expensive than standard lenses. By attaching it between the camera and the lens, Extension Tube will change your lens into macro lens