TRUE COLOR: This VND filter features our hd-quality optical glass with True Color film to produce accurate colors with no noticeable color shifting reducing post-processing time for color correction. VARIABLE ND FILTER: The True Color Variable ND filter is an all-in-one filter that reduces light from 1 to 5 stops making it perfect for shooting in various situations with shifting light conditions. ND16 FILTER: The Swift 4-Stop Neutral Density filter mounts on the Variable ND to allow for 6-9 stops of reduced exposure. It can also be used on its own with the Swift adapter (sold separately). NO VIGNETTING: The system is designed to eliminate vignetting at 18mm when stacking both filters. However vignetting may occur at wider focal lengths so be sure to test your setup before shooting. PRESSURE MOUNT: The NiSi Swift filter friction mount keeps it securely attached to your lens at all times giving you peace of mind. No need for unreliable magnets getting dislodged!