If your LHS can't get the 12.25 x 3.75 APC props order them through Tower Hobbies. I ran this prop on my Magic and it didn't work all that good. I used the stock muffler. Then I made a mouse can muffler and then it worked great. Also if you don't want to make a mouse can muffler try a Tower Hobbies 46 muffler. They only cost $13. and they will give you the power to pull the APC prop. You could order the props and muffler at the same time.