As randy41 said, "you will get a different opinion on props" -- he's right. I agree with his 11-6 choice & Bubbagates 11-5 choice, but I disagree with randy41's 10-6 (not enough prop for a TT .46 pro -- unless it is for break-in) & I disagree with bubbagates 11-7 (too much prop for a TT .46 Pro -- particlarly on a slow draggy crawler like the Kadet Mk II). An 11-4 is another viable choice if you stay away from full throttle in level flight.