Features 1、The inner hole size is 1.5-25mm, the outer diameter size is 37mm, and the thickness size is 5.5mm. 2、It is processed and manufactured with high‑quality precise technology. 3、The material uses high-quality aluminum alloy, which is reliable and durable. 4、Suitable for optical applications, suitable for a variety of optical instruments, cameras, etc. 5、Compact and practical design make the diaphragm works more stable. Specification Item Type: Iris Aperture Material: Aluminum Alloy Color: As shown in the picture Model: SK25 Inner Hole Size: Approx.1.5-25mm / 0.06-0.98in Outer Diameter Size: Approx.37mm / 1.46in Thickness: Approx.5.5mm / 0.22in Application: Optical applications Blades: 14 Package List 1 x Iris Aperture