FED. Interesting bat situation I had. Batter grounds out, inning over. Catcher says that bat had a rattle. I didn't hear it. I go check the bat between innings and shake it and hear nothing. Don't see that bat again until same batter comes up later. Foul ball and catcher says there it is again (rattle). I hear nothing. Next swing is ground ball out. Catcher says didn't you hear that? I heard something different and told the catcher. He picks up the bat and taps it against the plate and we hear a slight muffled rattle. I pick up the bat and shake it and feel, more than hear, something loose inside. I tell the coach it's out of the game due to rattle. His batter says it's the power disks. While shaking it for the coach we hear nothing and coach in good humor says I'm hearing things but bat is gone. Post game I google "power disk" and get this link:
2012 Louisville Slugger TPX EXOGRID2 BBCOR: BB12EX2 Adult
In the reviews it seems the power disks can come loose but also can be reseated. Anyway, once I hear a rattle the bat's out of the game.