Every pair of Ray-Ban or Oakley sunglasses carries a model number — a short code printed inside the temple arm that tells you exactly which frame you own and which compatible replacement lenses will fit it. Learning how to find your sunglasses model number takes about thirty seconds once you know where to look, and it is the single most useful thing you can do before ordering aftermarket parts. This guide decodes the whole string, digit by digit.
What the code inside your temple arm means
Fold your sunglasses open and look along the inside of the temple arms — the two side pieces that rest over your ears. Somewhere on that inner surface you will find a printed or engraved string that looks something like this: RB4165 54□17 145. It looks cryptic, but every block has exactly one job, and together they describe your frame completely.
The model number: RB4165
The first block identifies the frame itself. RB2140 is the classic Wayfarer, RB2132 the New Wayfarer, RB4165 the Justin, RB3025 the Aviator. Oakley pairs model names with SKU codes: OO9102 is the Holbrook, OO9013 the Frogskins, OO9014 the Gascan. This is the number that matters most when you shop for replacement lenses, because the lens shape is unique to each model — a Wayfarer lens will not sit in a Justin frame, even though the two look similar at arm’s length.
The lens size, or caliber: 54
The first number after the model code is the lens width in millimetres, measured horizontally across one lens at its widest point. Many frames are produced in more than one size — the Justin comes in 51 and 54, the New Wayfarer in 52, 55 and 58 — so two pairs of the same model can need completely different lenses. If you note only one number besides the model code, make it this one.
The bridge width: □17
The small square (□) is simply a separator. The number that follows it is the bridge width: the distance in millimetres between the two lenses, across your nose. It does not change which lenses fit, but it confirms you are reading the code in the right order — lens size always sits before the square, bridge width after it.
The temple length: 145
The final number is the length of the temple arm from the hinge to the tip, in millimetres. 140 and 145 are the most common on adult frames. You will need it if you ever order replacement temple arms — we cover that measurement in detail in our guide to replacing temple arms at home.
Where to look on Ray-Ban frames
Ray-Ban prints the full size code on the inside of the left temple arm, reading from the hinge outwards. The right arm usually carries branding and the place of manufacture instead. On acetate models like the Wayfarer the code is pad-printed and can fade after years of sweat, sunscreen and handling; on metal frames like the Aviator it is engraved and survives almost anything. You may also spot a colour code such as 601/8G after the model number — that describes the frame finish and lens tint the pair shipped with. It is handy if you want your new tint to match the old one, but it is not required to find a compatible lens: model plus caliber is enough.
Where to look on Oakley frames
Oakley does things slightly differently. Most frames carry the SKU on the inside of one temple arm — a code beginning OO, four digits, then a dash and a colourway number, for example OO9102-01. Many models also have the name itself (Holbrook, Frogskins, Gascan) moulded or printed inside the temple or under the nose bridge, which makes identification easy even when the finer printing has worn away. On some older sport frames the size numbers are missing entirely; in that case the SKU alone is enough, because most Oakley models are cut in a single lens size. Once you have it, our Oakley-compatible replacement lenses are organised by model, so finding your fit takes seconds.
What to do if the code has worn off
Faded printing is the most common reason people get stuck. No code, no panic — work through these four steps:
- Measure the lens width. Lay a ruler across the front of one lens at its widest point and read the millimetres. That number is your caliber, and it narrows the search immediately.
- Check your purchase history. Order confirmations from optical retailers almost always list the full model and size code, even years later.
- Compare silhouettes. The Wayfarer’s tilted trapezoid, the Holbrook’s rounded rectangle with keyhole bridge, the Aviator’s teardrop — frame shapes are surprisingly distinctive once you put photos side by side.
- Send us photos. A straight-on shot of the front, one of each temple arm and your lens measurement is normally all we need to identify the model for you.
Found your code? Don’t replace them — revive them
With the model number and lens size in hand, the hard part is done. Browse our Ray-Ban-compatible replacement lenses and Oakley-compatible ranges: 15+ colours, polarized and non-polarized options, all precision cut with full UV400 protection and designed for easy at-home installation. Every order ships free worldwide and is covered by our 3-year warranty against manufacturing defects, with 14-day returns if you change your mind. SunglassRevivers parts are independently manufactured compatible replacements — they are not products of Ray-Ban®, Oakley® or any frame brand, whose names appear here only as compatibility references. Your frames are still good. Give them new eyes.