The align pro blades are one of the best upgrades you can add to your Belt CP. They are generally pretty well matched out the packet in terms of Centre of Gravity (CoG) and Balance, compare this to the Esky blades which usually require mountains of tape to get these right! To use these with the Belt CP you need to add a 1mm shim or washer either side of the blade so it fits snugly in the Blade Holder. If you are using these with the stock plastic blade holders then you will need to grind down the root of the blade to fit in your blade holders see the guides section for photos and instructions on fitting to the Belt CP.