i got this unit from hurc for $17 and it works great[can't beat the shipping price
]....but as said before the results are that most of the apc props are not to bad that i'v cheched. at the most i had to add a very small amount of tape to one side to balance. hope the dubro unit works for you. i like to check my props just cause i'm a little ocd on trying to do the best i can preping birds to fly right.