Made of Optical Glass Variable ND Filter from 1.5 to 10 Stops Scratch, Moisture and Impact Resistant Lighting Fast Filter Installation with its Strong and Practical Magnetic Mount Technology Multicoated Surface Allows Increased Light Transmission and Reduces Glare Works with off the shelf lenses 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