I've used the Dyna Beads and they work well, but have since changed to the Centramatic System. Same principal, just you never have to replace or try to capture the beads. They are contained in liquid medium in a disk that mounts on the inside of the brake disk. Unless you're looking for them, you want notice them. They work every bit as well as the Dyna Beads. They've been using the Centramatic Systems on Over the Road trucks for years. They are expensive though.