Octagonal fronts change where the hinge sits compared with a round or square frame, and the Ray-Ban RB3556N's eight-sided front places it at a sharper angle than either. This compatible pair is cut to the 3556N's 145mm metal-arm spec with that hinge angle accounted for, so it seats the way the model's own arm would.

Angular fronts like this one put more repeated stress on the joint where the arm meets the hinge, since the arm has to open past a sharper corner than it would on a rounder frame. That joint is usually the first thing to loosen, well before the plating or the length of the arm shows any issue. If tightening the hinge screw doesn't fix a wobble, the joint itself has likely worn out, and the arm is the part to replace.

Frequently asked questions

What if the arms arrive and the hinge doesn't line up with my frame?

Because each pair is listed against a specific model, in this case the 3556, mismatches are rare, but you're covered by a 14-day return window if the 145mm arms don't align with your hinge.

How do I know these arms will fit my Ray-Ban frame?

These arms are made specifically for the 3556, matching its 145mm length and Rectangle hinge design, so they attach to your existing screws and hinge without any filing or adjustment needed.

Can I replace just one arm, or do I have to buy both?

You can order a single side if only one arm on your 3556 is broken or scratched, or buy the pair if both need replacing — either way they match the 145mm length exactly.

Is it worth buying new arms instead of a whole new frame?

Replacing both arms on the 3556 costs from €26.95 with free worldwide shipping, far less than a new frame, and it's backed by a 3-year warranty against manufacturing defects on the 145mm hardware itself.