The Ray-Ban RX6456 has an irregular, sculpted metal front paired with 140mm metal arms shaped to follow that asymmetry. This aftermarket set is cut to the same irregular profile, so the arm curves into the hinge the way the factory temple did instead of the simpler bend used on a standard square or round frame. Because the shape isn't symmetrical, the two arms aren't always interchangeable side to side, so it helps to note which one came off which side before ordering a single replacement.

Irregular fronts like the 6456's don't distribute hinge stress evenly, so one arm can loosen noticeably before the other does. It's worth checking both sides rather than assuming symmetry, and swapping only the arm that's actually worn is usually enough — there's no need to replace both temples at once. Fitting one side at a time and testing the fold before moving to the other side also helps catch a mismatch early.