The red Filter Adapter from Fenix is easy to attach and remove, and requires no modification to your flashlight. The filtered light protects night-adjusted vision, and red light is outside the visible range of many game animals, so you can signal to partners, read or navigate without alerting your quarry. It also has a low-light signature so it's harder to detect, even to those who can see it.. Made of PC2805 polycarbonate, it is temperature and impact resistant. This filter is compatible with Fenix PD35, PD12, and UC40 flashlights. It comes ready-to-use in clamshell packaging.