This is a pair of 10 x 7 x 3 (3 bladed) counter rotating propellers.
These are the props I use for both the HC Hobby Mosquito and B-25, whether I'm using a 3 or 4 cell battery (you could use a 9" on the 4 cell, but I don't) If you use it on the Mosquito, you need to carve a bit of plastic from the spinner's blade holes to enlarge them, since these are more paddle like props than the originals. That's one of the things that gives them so much OOMMPH! With these props, both those planes go from pussycat to Cheetah- just the way I like them!
HC Hobby A-10 Landing Gear (1 pair, 2 pieces).
HC Hobby B-25 Mitchell Electronic Speed Control (ESC) 30Amps.
HC Hobby B-25 Mitchell Landing Gear (3 pieces).
HC Hobby B-25 Mitchell Main Wing Set (one pair, 2 pieces)
2 Counter-Rotating Props fits either the HC Hobby B-25 Mitchell or the HC Hobby Mosquito