The Canon E-43 Lens Cap for 43mm Diameter EF-M Lens is a
protective cap that fits on the front end of EF-M lenses with a filter
diameter of 43mm. It works with the EF-M 22mm f/2 STM lens. The EF-M
lenses are compatible with the EOS-M mirrorless digital camera. The cap
prevents dust and dirt buildup when the lens is not in use, and also
safeguards it against scratches, bumps and other light impact.