Hi trere! Playn' Dayz Ive always wondered "how will I recognize friendly players if it was a real live?" Here's the answer coming from my experience playing airsoft (what a pity this gadget helps only at night) this is a IR marker which makes flashing lights which can be seen while using Nightvision. Different teams can use this markers to recognize friendly or not. But what will you do if both sides has IR markers? every marker has а control knobs to change the frequency of flashing. I guess guys who played Arma 2 know what i mean. And here's the link af testing those strobe markers http://www.youtube.com/watch?v=7ti3GJo12p0 With best regards Alex Chernyy