The Sound Deadening System is engineered to eliminate noise and shock throughout the crossbow for deadly suppressed performance. This four-component package works in sync to reduce vibration and noise when the crossbow is fired, resulting in a much smoother shooting experience and effectively increases your success. Works on all Excalibur Crossbows. Includes: Over-molded Rubberized Stirrup Ex-Shox Sound DampenersString StarsR. A.V. S. Limb Silencers Excalibur Sound Deadening System incl. Exact Fit, R. A.V. S, String Stars & Over-Molded Foot Stirrup 95913