Using this Fenix AOF - L flashlight filter adapter is easy. Just fit it onto your compatible Fenix flashlight. For the red filter, use it when you're out in the dark and need to maintain your night vision, like when you're hunting. The green filter is great for reading maps during night hikes. And the blue filter is for finding blood trails if you're tracking an animal. When it comes to maintenance, use a soft, dry cloth to clean the adapter regularly. Keep it in a cool, dry place when not in use. Avoid exposing it to extreme temperatures or harsh chemicals. Also, make sure to check the fit on your flashlight before each use to ensure it's secure.