... : *M25,27,28,30,30.5,34,40.5mm,43mm,46mm,49mm to 37mm *M37,40.5,43,49,55,58 ... are labeled from the camera to the filter. For example, a 25.5mm to 46mm step up ring is used for a ... lens) with 25.5mm threads. The adapter will allow a 46mm filter (or other adapter ring) to fit. Adapter rings can be ... stacked. To use a 49mm filter on a 25.5mm camera lens, first use a 25 ...