The QF65 Clear UV Filter kit consists of a black retaining ring and two clear filter disks. Remove the clear protective film from both filters. For special color lighting effects, a colored gel can be added. The optional QF66 accessory is an assortment of 7 colored gels pre-cut to fit the Qflash. To add a colored gel, remove the two filter disks from the retaining ring. Insert a pre-cut gel between the disks or cut a colored gel (not supplied) the same size as the filter disks. Insert the disk assembly inside the retaining ring. Snap the diffuser onto the reflector.