Look where you mount the servos for the ailerons they should have a red round quality control stamp there, also at the wing root(where the wings connect).
That's what Horizon told me and mine have it.
Haven't had any problems.
That's a great price.
Also watch out the manual picture for the dihedral is wrong but is right on the next page step 10 in text.
Just be sure that the dihedral is at 0.