The kase magnetic cpl variable nd filter 1.5 5 stop is a combination of two filters in one a circular polarizing cpl filter and a variable neutral density nd filter. Cpl filter reduces glare and reflections from non metallic surfaces, such as water and glass. It also helps to saturate colours and make images more vibrant. Variable nd filter reduces the amount of light that reaches the camera sensor, which allows you to use slower shutter speeds and wider apertures in bright conditions. This can be useful for creating effects such as motion blur and bokeh.