When placed in the bottom Harmonic Damper hole the Harmonic Stabilizer will give optimum performance. Another Harmonic Stabilizer can be purchased and put in the top damper hole for added weight but little is gained in post residual vibration. One Harmonic Stabilizer will be standard issue on the majority of newer model bows and can be purchased as an accessory to retrofit most Mathews bows currently equipped with Harmonic Dampers. Visit your local Mathews retailer and feel the Harmonic Stabilizer difference for yourself.