Canon YG2-2023 Lens Mount
Canon YG2-2031 Power Diaphragm
Canon YG2-2060 AF-MF Switch
Canon YG2-2062 Power Diaphragm
Genuine Canon power diaphragm assembly for the EF 24-70 2.8 L USM lenses. Made by Canon Japan. Unfortunately, this part has been discontinued and is no longer available.
TechNote. Many times the issue you may have with your lens points to the power diaphragm unit, when actually the FPC (flexible printed circuit) has broken and needs replacement. In stock here.