Circular PL filter helps to increase colour saturation and to reduce reflections from water, glass and other surfaces. ND filter can reduce light intensity without changing color balance. There is the occasion that you want to use both C-PL filter and ND filter to reduce reflections and set the slow shutter when shooting water splash, streaming, etc. This CREATION C-PL/ND filter has dual purpose polarizer and ND functions two-in-one and there is no need to stack two filters. This filter employs slim profile frame (thickness is 5.0mmwithout thread) so that vignetting can be prevented.