REVORING is an innovative variable step ring that allows one filter to be attached to a variety of lenses.The structure applies the principle of aperture blades, making it possible to attach one filter to lenses with multiple apertures.Thin frame A screw-on CPL or ND filter can be used with a 16mm lens without vignetting. If you frequently use variable ND with a 16mm lens, we recommend the REVORING VARI