Meike MK-N-AF3C-BLACK Tube diameter : Macro extension tube can be used alone or in superimposed,When using the extension tubes alone (10 mm or 16 mm) or combination (10mm+16mm=26mm), the focal length of lens should be greater than the length (10mm 16mm or 26mm ) of the tube. Compatible with :Nikon camera mirrorless cameras J1 J2 J3 V1 V2 Take close-up of small objects, insects , flowers or more item small and easy to carry, Nice construction and simple to use. It enables you to use all shooting modes of the camera, exposure compensation is required. Getting closer has the effect of magnifying your subject (making it appear larger in the viewfinder and in your pictures) The extension tube is designed for Nikon N-Mount lens mounting at a higher magnification at a closer distance