JJC ALC-MX1 Auto Self-Retaining Lens Cap for PENTAX Camera MX-1 (Black) Auto Lens Cap Opens and closes automatically in sync with lens movement. A new optional lens cap has been developed. Utilizing hinges, it opens and closes automatically with the extension and retraction of the lens. Without touching the lens cap, the camera responds instantly to sudden shutter opportunities by just turning on the power. Protect the lens with a lens cap that can't be lost or forgotten.