Check the listing for details. 37mm-30mm Metal Step Down Ring Camera Lens Filter Adapter Ring Aluminum Filter. Condition: New. Listed at 13.16 USD. The camera lens adapter ring can be installed in front of the lens, allowing you to use filters and accessories different from the size of the camera lens. The adapter ring can change-over lenses of various sizes, so that you can share the same filter, shutter, additional lens, etc.SpecificationColor: BlackMaterial: Aluminum AlloySuitable for: all 37mm lenses and 30mm filtersOverall Size: 39x5.5mm/1.54x0.22inch(Dia.H)Male Thread: 37mm/1.46inchFemale Thread: 30mm/1.18inchPackage List: 1 x Filter Adapter Step Down RingAdvantageThe adapter ring is made of aluminum alloy and coated with matte black electroplated coating, which can resist corrosion and other wear elements often encountered in outdoor photography.