The 77mm ExpoImaging ExpoDisc 2.0 White Balance Filter features 18% calibrated light transmission for ensuring correct exposure and white balance settings while shooting and editing. It attaches to lenses or filters with a 77mm thread via a button-activated spring attachment. This is even compatible with low-profile filter threads. Also, the ExpoDisc 2.0 can be used with smaller lenses by simply holding the filter in front of the lens. The ExpoDisc 2.0 can also be used to dust map your sensor due to the neutral image it creates. Additionally, two warming filters are included that are inserted into recesses on the face of the filter. These two levels of warming add warmth for more pleasing skin tones.