If you already own a DDR4 stick but are unsure about it's serial number then you can use CPU-Z to help you identify it (in the spd tab)!
| RAM serial number |
|---|
| BLE8G4D26AFEA.16FA |
| CMU32GX4M4C3200C16 |
| F4-3200C16-8GTZR |
| VMA49UG-MEC1U2BQ1 |
| F4-2400C15-8GTZR |
| CT8G4DFS8213.C8FBR |
| DDR4-2400 CL16 8GB |
| F4-3200C14-8GTZKW |
| F4-3200C14-8GTZR |