When you want to use a filter on a lens with a smaller filter thread size, you need a step-up adapter ring.It is a metallic Step-Up Lens Filter ring Adapter which allows a filter attachment with larger thread size to be used with a lens with smaller thread size.It works for Filter,Lens,Lens Hood, Lens Cap etc.Manufactured from Special Aluminium alloy, it has high strength and good impact resistance. if you own lenses with varying filter-thread sizes, stepping rings weigh and cost less than multiples of comparable glass filters and lens accessories. Owning stepping rings is a desirable solution that should please both your wallet and your shoulders and back.