Use this set not downgrade the optical quality of your lens. Sharpness and Saturation can be still maintained. But they are not meter-coupled. They do not preserve the automatic diaphragm. It should be used with manual lenses with their own aperture dial. On most lenses, the manufacturers provide a focusing mechanism that extends only a few millimetres, partly to keep down costs and partly to restrict the lens to extensions for which its optics are optimised. To provide additional extension, one or more extension tubes can be added between the camera and the lens, to make the lens focus at closer distances and therefore produce higher magnification. Colour:Black Material:Plastic Package Contents: 1 * M39 close-up ring Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.