Feature: 1. Exquisite and fluent appearance, it uses high quality craftsmanship, which can bring you an excellent visual and tactile enjoyment when you use it. 2. Removable design, its installation process is more convenient, it can create more possibilities, and it is easier to combine with other equipment. 3. Using high quality aluminum alloy material, it is corrosion resistant and durable, does not fade easily, can be used in various situations, and has a long service life. 4. Stable performance, high accuracy, can meet the high standards of the industry, more widely used in the field of optics, it is a good helper for you to control the light. 5. Compact structure design, its body has no burrs and pressure points, is not easy to deform, and has strong flexibility, stability and practicality. Specification: Item Type: Diaphragm Model: SK189 Material: Aluminum Alloy Uses: It can be used as accessories for lasers, cameras, and optical platforms. Outer Circle Size: Approx. 31mm / 1.2in Inner Hole Size: Approx. 18.9mm / 0.7in Thickness: Approx. 4mm / 0.2in Number of Blades: 10 Pieces. Package List: 1 x Diaphragm Note: Please note that the new type and old type of this product will be sent randomly, and make sure you will not mind before ordering.