Got this for my Syma S107g as a replacement rear rotor. It was suggested for it's increased forward speed.For forward movement, it worked great!...at the expense of nearly all reverse movement. Going backward was painfully slow.Then after 4 flights one blade had a crack nearly through the whole thing. The next flight, the blade broke off.I'm glad I bought the 2 pack rather than the 4 pack.These things are fragile.