"Simple Mechanism No rocket science here, just a well made lens cap with strong springs from Breakthrough Photography. Strong springs ensure a tighter fit, longer life and prevent failure in the field. Fits all 46mm camera lens, filter, manual or autofocus, digital or film. The lens cap protects your camera lens from external agents such as dust particles, water splashes, sun rays and also protects from scratches. Made from 100% recycled plastic for extra durability Snap-on center-pinch lens cap is easy to use. Simply pinch the center to quickly attach to your camera lens. Easy to remove, even with lens hoods on Strong springs Tighter fit and longer life Protection From External Damages This cap protects your camera lens from external agents such as dust particles, water splashes, sun rays and also protects from scratches during storage and walking around. Snap-On Center Pinch Design Lens Cap Our snap on center pinch design cap makes it easy to attach and remove, even with a lens hood on. The lens cap is manufactured from 100% recycled plastic for extra durability. Universal Compatible Camera Lens Cover This camera lens cap is compatible with all 46mm camera lenses such as Nikon, Canon, Sony and other DSLR cameras"