Adapter ring is used between camera(or projector) and lenses,it could mount kinds of conversion lenses,such as telephot ... For example, a 25.5mm to 46mm step up ring is used for a camera (or lens) with 25 ... adapter will allow a 46mm filter (or other adapter ring) to fit. Adapter rings can be stacked. To ... then a 46mm to 49mm step up ring. Specification of our adapter ring as follow: *M25,27,28,30,30. ...