Primacoustic RX5 - DF Recoil Stabilizer, Down-Fire 7.5" x 9.5"The angled Primacoustic RX5a Recoil Stabilizer is a unique speaker mounting device that eliminates disruptive resonant coupling from the loudspeaker to the stand. At the same time the Recoil Stabilizer provides a stable base that reduces recoil from the loudspeaker's forward energy. Made from three basic components, the Recoil Stabilizer is essentially a platform for the loudspeaker that features a high density urethane base that isolates the speaker