1st, 2nd, 3rd axis... you probably see this on every single sight on the market and honestly have no idea on what it means. Think about it like this. Every sight has a level built into it. It helps guide your arrow on the correct path in relations to your pins. If that level isn't "really" level, then your accuracy will go severely downhill the farther you get out. With the use of the Hamskea Third Axis Level, you can check all of that yourself and it's actually a lot easier than you'd think! If you're struggling at distances or in incline/declines, then your 3rd axis is the most common issue. You'll be smoking 12's in no time!