It becomes extremely useful when carrying lenses around or simply for storing purposes. Lens Cap E-43 is compatible with the EF-M 22mm f/2 STM lens. Compatibility -- EF-M 22mm f/2 STM -- EOS M Black EF-M 18-55mm IS STM Kit -- EOS M Black EF-M 22mm STM Lens Kit -- EOS M White EF-M 22mm STM Lens Kit