This filter step ring is made specifically with the Starizona Filter Slider system in mind.

It is zero profile, adding no extra height to the 1.25" filter. It steps the M48 threads of a standard 2" filter down to the 1.125" threads of a standard 1.25" filter.

The step ring has a 2" outside diameter, so it can also be used in many other applications in addition to the Filter Slider.