Canon EF 24-70mm f/2.8 L USM disassembly and replacing the aperture flex cable,Canon Support for EF 24-70mm f/2.8L USM | Canon U.S.A., Inc.,For Canon EF 24-70mm f / 4L IS USM Lens Aperture Unit Aperture Assey Repair Part | eBay,Canon 5175B002 USM Standard Zoom Lens,How to repair Canon lens EF 24-70 USM F/2.8 - 1-st Version - Exchange diaphragm unit,