1、[Inner Diameter] The iris aperture diaphragm has an adjusting inner diameter 1 to 12mm, an outer diameter of 28mm. 2、[Function ] The aperture diaphragm provides small holes of different diameters in the optical system to meet different light throughput requirements. 3、[Simple Operation] Change the diameter of the aperture diaphragm by the handle, very easy to operate in practice and friendly to novices. 4、[Made of Aluminum Alloy and Stainless Steel] The camera aperture diaphragm is made of aluminum alloy and stainless steel for reliable performance and ruggedness. 5、[Compact Appearance] This aperture diaphragm uses a compact and practical design, making the aperture diaphragm a practical way to work.