This filter fits these lights ONLY: FD41, TK20R, TK16 V1, TK15C, TK15UE, TK09, HP15UE (not current version), HP30, HL40R and the PD40R V2.0. PVC plastic filters are available in Red, Green, and Blue. The filter converts the focused high-output beam of a normal flashlight into a soft, wide-angle, diffused flood beam. It is great for close-up and low-light applications, such as wide-area lighting, short-distance reading, camping, etc.

 A red filter helps to preserve your night vision since red light does not cause your pupils to dilate as much as white light does.

A blue filter is great for tracking blood, making it a great option for hunters

A green filter is ideal for hunters and fishermen because it is a very soft light that will not alert game. However, it is brighter than all the other colors, which makes it easier for navigation and it also makes it easier for others to see you.