The Altra Reinforced Concentric Outset System (A.R.C.O.S.) for 166 Shafts is designed to deliver unmatched durability and performance. Crafted from 7075-T6 aluminum, this system includes an insert that secures into the arrow shaft at a depth of 0.875 inches, while the outsert threads directly onto the insert, encapsulating the leading end of the arrow by 0.43 inches. Pre-installed rubber O-rings help lock the outsert in place, reducing vibration and enhancing concentricity for a more precise arrow setup and improved downrange accuracy. Available in four spine sizes, the A.R.C.O.S. system is perfect for those seeking optimal fit and performance.

Features:Fits Altra Arrows 166 Shafts;Machined from 7075-T6 aluminum for unmatched durability;Secure insert depth: 0.875 inches;Outsert encapsulates arrow end: 0.43 inches;Pre-installed rubber O-rings reduce vibration and improve concentricity;Comes in 12 pk QTY;Available in four sizes: 250, 300, 350, & 400 spine;50gn Total Weight;Accepts micro FMS insert weights;Enhances downrange accuracy and precision