Anton Chigurh spends a lot of this movie walking around with an air-powered steer killing device. Its primary purpose is making things dead by shooting a short needle directly into the skull. (At least it's less messy than a bullet?) But the steer-killer is a multipurpose tool, because Chigurh also uses it to punch out the locks of doors. Handy!
The only problem with this nifty device is that it looks awfully heavy and cumbersome to be toting around Texas. But when we see the damage he can do with it when busting into rooms, we realize why he bothers: not only is it an efficient killing machine, it does a great job of conveying his message.
Let's let Ed Tom explain how the thing works: "Shoots out a little rod about that far into the brain. Sucks right back in. Animal never knows what hit him." Ed Tom doesn't know why he's telling Carla Jean about this device. He says it's because his mind is wandering, but we think it might have something to do with his feels about how cold and robotic killing has become in the modern world. After all, to someone like Chigurh, people are nothing more than cattle—and the steer-killer proves it.