Feature:1. Provide small holes of different diameters in the optical system to meet different light transmission requirements.2. The compact and practical structure makes the diaphragm work more stable, light in weight and easy to operate.3. It is manufactured with high quality precise craftsmanship, with high quality, long service life, high strength and good durability.4. The inner hole enlargement and reduction range is 1.534mm, which can meet your needs and adapt to a variety of optical instruments, cameras, etc.5. The material is made of aluminum alloy, which is not easy to rust, has good hardness, corrosion resistance, low density, reliable and durable.Specification:Item Type: Iris ApertureMaterial: Aluminum AlloyColor: As shown in the pictureModel: SK34Outer Diameter Size: Approx.49mm / 1.93inInner Hole Size: Approx.1.5-34mm / 0.06-1.34inThickness: Approx.5.6mm / 0.22inApplication: Optical instruments such as lasering cameras.Package List:1 x Iris ApertureNote:1. Please allow 12in error due to manual measurement. Thanks for your understanding.2. Monitors are not calibrated same, item color displayed in photos may be showing slightly different from the real object. Please take the real one as standard.3. Please pay attention to the incisive edges of the blades, pay attention to safety when using, and do not put your hands on the blades.