Item Type: Aperture Diaphragm Material: Aluminum Alloy Gross Weight: 165g / 5.8oz Article Number: SK98 Inner Hole Diameter: Approx.6-98mm / 0.2-3.9in Outer Circle Diameter: Approx.130mm / 5.1in Thickness: Approx.12mm / 0.5in Blades Number: 20 Package List 1 x Diaphragm 1Aluminum Alloy: This adjustable diaphragm is made of premium aluminum alloy, which is wear resistant, reliable in performance and durable. 2Adjustable: Inner diameter of 698mm and outer diameter of 130mm, providing small holes with different diameters in the optical system to meet different light requirements. 3Zoom in and Zoom out: This aperture adjuster can zoom in and out according to the ratio of holes with different diameters in the optical system. 4Compact and Practical: The compact and practical design makes the diaphragm a more practical way of working, portable and convenient. 5Simple Operation: This iris diaphragm can change the diaphragm diameter through the handle, which is easy to use and operate, and can be used with confidence.