RB2447NM Round pairs a round metal front with 145mm metal arms, longer than the 140mm size used on most of Ray-Ban's round metal lines. This aftermarket pair matches both the extended length and the round curve, so the temple follows the front's arc into the hinge rather than sitting straighter like a square-frame arm would. Confirming the 145mm figure against the model code is worth the extra minute, since it's easy to assume a round Ray-Ban arm defaults to the more common 140mm length.

Round metal sunglasses like the 2447 put continuous curved tension through the arm rather than a single straight bend, which is part of why the hinge screw tends to loosen gradually rather than all at once. A gentle periodic tightening keeps the round shape sitting evenly rather than drifting to one side. Measuring the old arm before ordering, when it's available, is a simple way to double-check the 145mm figure without relying on memory.

Frequently asked questions

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 2447 is broken or scratched, or buy the pair if both need replacing — either way they match the 145mm length exactly.

My hinge feels loose — will new arms fix that, or is it the frame that's worn?

A new 145mm arm includes its own hinge barrel, so if the wobble is coming from worn threading on the arm side of the 2447, replacing it usually restores a snug, tight fold.

Are these official Ray-Ban replacement parts?

These are compatible aftermarket arms, independently produced to match the 2447's hinge and 145mm length. They aren't manufactured or supplied by Ray-Ban, just built to the same measurements so they attach correctly.

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 2447, mismatches are rare, but you're covered by a 14-day return window if the 145mm arms don't align with your hinge.