The New Magnetic Control System (MCS) by Tiffen is an elegantly simple way to harness magnetic power to swiftly and securely attach Tiffen filters to lenses’ fronts. Developed to eliminate the hassle of threading filters on and off, while maintaining a safe and positive lock, MCS makes installation and removal lightning-fast. Works with off the shelf lenses. Direct fits 82mm, 77mm and 58mm lens fronts with step-up rings for other sizes. Fast and easy, no tools needed for installation. No lasting modification to the original lens. Filter Instantly attaches to Magnetic Holder. Each filter comes with a front and rear magnetic lens cap.