At 140mm, the metal arms on Ray-Ban's RB4311N carry an aviator taper into a plastic front — a pairing this aftermarket set reproduces exactly, so the curve toward the temple tip and the hinge fit both match the factory geometry rather than the straighter arm used on Ray-Ban's square-fronted models. Ordering against the RB4311N code specifically, rather than a general description like 'aviator, 140mm,' is what keeps that taper accurate, since a few Ray-Ban lines share a broadly similar aviator sweep at a glance.

Metal arms like these can be gently reshaped by an optician to sit better behind the ear, something a plastic or acetate arm can't do without risking a crack. That small adjustment often solves a fit complaint that looks like it needs a whole new pair of arms. Comparing the new arm against the old one before fitting is also worth doing on a plastic-hinge frame like this, since a poor curve match puts uneven pressure on the socket rather than just looking slightly off.

Frequently asked questions

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

These arms are made specifically for the 4311, matching its 140mm length and Aviator hinge design, so they attach to your existing screws and hinge without any filing or adjustment needed.

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

Replacing both arms on the 4311 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 140mm hardware itself.

Are these official Ray-Ban replacement parts?

These are compatible aftermarket arms, independently produced to match the 4311's hinge and 140mm length. They aren't manufactured or supplied by Ray-Ban, just built to the same measurements so they attach correctly.

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 4311 is broken or scratched, or buy the pair if both need replacing — either way they match the 140mm length exactly.