Features 1、4‑60mm Adjustable: The inner hole diameter is 4‑60mm adjustable. The outer diameter is 82mm. And the small holes with different diameters are provided in the optical system to meet different light transmission requirements 2、Aluminum Alloy Material: The aperture diaphragm is made of premium aluminum alloy, which has the characteristics of reliable performance and firmness, and can be used for a long time. 3、Simple Operation: This is a manually adjustable aperture diaphragm. The diameter of the metal aperture diaphragm can be changed through the handle. 4、Compact Design: The mechanical iris aperture diaphragm adopts a compact design, is easy to install and does not take up too much space, which can become a more practical tool. 5、Applicability: This adjustable aperture diaphragm is suitable for cameras, microscopes, condensers and other machines, which can help them work better. Specification Item Type: Aperture diaphragm Material: Aluminium alloy Weight: Approx. 49g/1.7oz Product Number: sk60 Inner Hole Diameter: 4-60mm/0.16-2.4in Outer Diameter: 82mm/3.2in Thickness: 8mm/0.3in Number of Blades: 18 Package List 1 x Aperture Diaphragm