Step-Down rings allows to use smaller filters on larger lenses.
This enables to use 25mm filters on lenses with 30mm thread.
This enables to use 32mm filters on lenses with 42mm thread.
This enables to use 43mm filters on lenses with 46mm thread.
This enables to use 42mm filters on lenses with 48mm thread.
This enables to use 34mm filters on lenses with 49mm thread.
This enables to use 37mm filters on lenses with 49mm thread.
This enables to use 42mm filters on lenses with 52mm thread.
This enables to use 46mm filters on lenses with 52mm thread.
This enables to use 49mm filters on lenses with 52mm thread.
This enables to use 46mm filters on lenses with 55mm thread.
This enables to use 49mm filters on lenses with 55mm thread.
This enables to use 52mm filters on lenses with 55mm thread.