Product picture - Nimar Extension Ring with Mechanical Zoom Control & Lock for Canon EF 16-35mm f 2.8L II USM and f 4L IS USM Nimar, Extension, Ring, with, Mechanical, Zoom, Control, &, Lock, Canon, EF, 16-35mm, f, 2.8L, II, USM, f, 4L, IS, USM Click the image to close this page