This Haida Rear Lens ND Filter Kit contains four filters that are each compatible with the built-in rear filter slot of a Sigma 14-24mm f/2.8 DG DN Art lens for Sony E-mount or Leica L-mount camera, or Sigma 24mm f/1.4 DG DN Art lens for Sony E-mount. Each filter can be used individually to create a darkening of the entire image, allowing you to photograph with a wider aperture or slower shutter speed than normally required. By increasing your aperture or slowing your exposure time, you can control the depth of field and convey movement more easily. Neutral density filters do not affect the coloration of the image and are ideal for pairing with other filters. The kit's ND 0.9, ND 1.2, ND 1.8, and ND 3.0 filters provide a respective 3, 4, 6, and 10-stop exposure reduction. These filters are constructed from optical glass for clarity and color fidelity. To prevent internal ghosting and reflections, each glass surface includes 10 layers of anti-reflection coatings, which also offer greater protection to the filter substrate and help keep it clean for a longer period of time. The Nano coating associated with these neutral density filters provides an additional layer that results in an improved beading effect if their surfaces come in contact with water or oil, allowing for more efficient cleaning. A plastic case is included for storage and transport.