Another round of tips in tactical movement by Fox Airsoft and they talk about concealment and cover... "When you are out there playing, it's important to recognize what is the difference between concealment and cover. Concealment does not stop an incoming BB being shot at you, and cover is hard enough that it will. You will figure this out quickly when you get shot through shrubbery or something with similar density. Our suggestion if you are being fired upon is seek hard cover immediately and try not to move out in the open."