Compatible with the Ray-Ban RX3578V, this 140mm metal temple arm is built for the model's round shape and metal front, matching both the length and the curve the frame was designed around. A poor match on either measurement tends to show up as an uneven sit rather than an outright failure to close.Replacing a bent or worn temple arm is a much smaller expense than buying a new frame outright, especially when the round metal front is still in good shape. A matched 140mm aftermarket arm brings the RX3578V back to its proper fit without touching the part of the frame that never failed. It's usually the more sensible route once the front and lenses check out fine. It's also worth checking that the round front hasn't picked up its own wear at the same hinge point before ordering just the arm.

Frequently asked questions

What material are the arms made from, and will the color match my frame?

The arms are molded in an acetate or metal finish that matches the Round style of the 3578 closely, though very slight shade variation is possible since they're independently produced as separate aftermarket parts rather than cut from the same batch as the frame.

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

A new 140mm arm includes its own hinge barrel, so if the wobble is coming from worn threading on the arm side of the 3578, replacing it usually restores a snug, tight fold.

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

These arms are made specifically for the 3578, matching its 140mm length and Round hinge design, so they attach to your existing screws and hinge without any filing or adjustment needed.

Are these official Ray-Ban replacement parts?

These are compatible aftermarket arms, independently produced to match the 3578's hinge and 140mm length. They aren't manufactured or supplied by Ray-Ban, just built to the same measurements so they attach correctly.