Mechanical Iris structure designed for 3d print. There are 5 leaves. Then you rotate the "Drive Part"or the middle plate, the center hole can open or close gradually. The center hole is diameter 10mm, the outer size is diameter 45mm and thickness is 8.2mm. More: www.tanerxun.com Files: https://www.cgtrader.com/3d-print-models/hobby-diy/mechanical-parts/3d-printable-mechanical-iris-structure-3dp5bl-ro-gear-d10a