Each Axis shaft has the "Hidden Insert Technology" (short HIT) and therefor you need a HIT-insert. Normally these shafts are already delivered with such! So be aware that you don't buy additional ones. > - X HIT conventional inserts included From [Lancasterarchery][1] You can get them for example [here][2]. ---------- The Deep Six RPS Steel insert is also compatible but I would absolutely recommend the HIT inserts. > - X HIT conventional thread inserts - compatible > - Deep Six RPS steel inserts - compatible From the official [Axis product site][3] *P.S.: Axis absolutely rock! =)* *"I shoot Axis because they're tough shafts, but more importantly, I shoot them for the increased penetration I get on big game."* - Fred Eichler [1]: http://www.lancasterarchery.com/easton-axis-n-fused-carbon-arrow-shaft.html [2]: http://www.3riversarchery.com/easton-axis-hit-insert-kit.html [3]: http://www.eastonhunting.com/products/arrows/axis