Depending on the age of the watch, Rolex reference numbers can range from four digits to six digits in length. While all of the digits have significance and help describe the watch, the last number in the reference number is, in fact, a material code – which tells you what metal was used for the construction of the watch.
| Metal Type | Code |
|---|---|
| Stainless | 0 |
| Stainless Stainless & Rose Gold | 1 |
| Stainless Steel & Platinum | 2 |
| Stainless Steel & Yellow Gold | 3 |
| Stainless Steel & White Gold | 4 |
| Gold Shell – Date Models | 5 |
| Rose Gold | 5 |
| Platinum | 6 |
| 14k Yellow Gold | 7 |
| 18k Yellow Gold | 8 |
| 18k White Gold | 9 |
