4*60 with TT.61??
I have the TT61 Pro on a Global Right Flyer 60H trainer. I got a couple of APC 13x4W "3D Fun Fly" Series props and they worked great on my engine/plane. I've been learning to land and have broken both 13x4Ws and all 3 of my APC 12x5s. I switched to a Master Airscrew 12x6 with the white tips. It has survived my landings better than the APCs.