• IBS™ Locks the Inner Barrel Securely into Place to Prevent Any Shaking Before the BB Exits the rifle • Increase Accuracy and Grouping Consistency • Muffles the Level of Noise From the Shots Fired The IBS*' Inner Barrel Stabilizer Unit is designed to lock down the guns inner barrel to prevent any vibrational movement at the muzzle which causes major inconsistencies to your shots over long distances. Once installed, your ARP9/556 performance will noticeably shoot straighter and further with a proven improvement in your groupings Lock-down your Inner Barrel now and improve your accuracy!