Altra 166 A.R.C.O.S. Reinforced Concentric Outsert System - Durable Foot Support for Running, Hiking & Outdoor Activities

The Pinnacle of Precision & Performance™ Altra Reinforced Concentric Outset System (A.R.C.O.S.) fits our Altra Arrows 166 Shafts and are machined out of 7075-T6 aluminum for unmatched durability and performance, with optimal fit options. 
The insert secures into the arrow shaft at a depth of 0.875", while the outsert then threads directly onto the insert and encapsulates the leading end of the arrow at 0.43" creating unmatched durability. Essential rubber O-rings come pre-installed on the insert within the A.R.C.O.S., as they aid in locking the outsert in place which reduces vibration and improves concentricity between the outsert to the insert for a more precise arrow set up and down range accuracy.

• Accepts micro Forward Mass System (FMS) insert weights
• Fitment:  Altra 166 shafts 250, 300, 350, & 400 spine
• Construction: 7075-T6 aluminum 
• Weight: 50 gr total 
• Each outsert is spine specific, and the cosmetic grooves provide a visual confirmation of which spine each outsert is for: 250 -no groove, 300 -1 groove, 350 -2 grooves, 400 - 3 grooves
• Quantity: 12-pk