This ND400 Magnetic Clip-On ND Filter from H&Y is compatible with select 67-82mm RevoRing filters to reduce exposure by 9-stops for finer image control. The added density can be used to increase shutter speed for increased image blur, like smoothing out water surfaces or to emphasize motion. It can also be used to narrow depth of field and increase background bokeh to better isolate the subject of an image. In addition, it can help resolve the phenomenon of the "X-pattern" that can form when using a variable neutral density filter on a wide-angle lens. By adding density to increase the aperture opening, the X-pattern on the image can be reduced or eliminated.

This neutral density filter is made of 2mm-thick optical glass with multicoating for optimal light transmission, and resistance coating to repel fingerprints, oil, and water for easily cleaning. The magnetic frame attaches easily to the RevoRing, and multiple filters may be stacked for greater effect.