If you have tried the Align Pro blades then you know about the quality. As your flying progresses you may want the durability that the fibers can give you. Made from light fiber glass material using an injection moulding process and having a rigid carbon fiber rod running inside, these blades can stand higher headspeeds and more aggressive flying than the Pro blades. Note: If you are using the stock plastic head then you need to grind the root down so they fit. You also need a couple 1mm spacers either side. The CNC head just needs the spacers.