Item Type:Iris Diaphragm_x000D_SK25:_x000D_Magnified Diameter: 1.5-25mm_x000D_Material: Metal_x000D_Outer Diameter :44mm_x000D_Inner Diameter: 25mm_x000D_Thickness :8mm_x000D_14 blades_x000D__x000D_SK23_x000D_Outer Diameter: 37mm_x000D_Minimum Aperture Diameter: ?1.5mm_x000D_Maximum Aperture Diameter: ?23mm_x000D_Material:Metal_x000D_Thickness: 7.0mm_x000D_12 Blades_x000D__x000D_SK12_x000D_Outer Diameter: 19.8mm_x000D_Minimum Aperture: ?1mm_x000D_Maximum Aperture: ?12mm_x000D_Material: Metal_x000D_Thickness: 5.0mm_x000D_10 Blades_x000D__x000D_SK8_x000D_Outer Diameter: 14.8mm_x000D_Minimum Aperture: ?0.8mm_x000D_Maximum Aperture: ?8mm_x000D_Material: Metal_x000D_Thickness: 4.5mm_x000D_8 Blades_x000D__x000D_SK6_x000D_Outer Diameter: 13.0mm_x000D_Minimum Aperture: ?0.8mm_x000D_Maximum Aperture: ?6mm_x000D_Material: Metal_x000D_Thickness: 6mm_x000D_8 Blades 1Small apertures of different diameters are provided in the optical system to meet different light transmission requirements. 2Change the diameter of the aperture by the handle. 3Metal material, reliable performance, durable. 4We provides 5 kinds of aperture for you to choose from to meet different requirements. 5Compact and practical design make the diaphragm works more stable.1 x Diaphragm