| Product | Revision | Firmware ID | Date Available | Serial Number |
|---|---|---|---|---|
| SEL-451-1 | R202 | SEL-451-1-R202-V0-Z004004-D20090213 | 2/27/09 | 2009058001 |
| SEL-451-2 | R126 | SEL-451-2-R126-V0-Z100011-D20121207 | 12/21/12 | 1123560001 |
| SEL-451-4 | R126 | SEL-451-4-R126-V0-Z100011-D20121207 | 12/21/12 | 1123560001 |
| SEL-451-5 | R324-V0 | SEL-451-5-R324-V0-Z027013-D20200229 | 4/11/20 | ~1201020001 |
| SEL-451-6 | R400-V1 | SEL-451-6-R400-V1-Z100100-D20191210 | 12/14/19 | ~1193470001 |
The Firmware IDs for older versions of the firmware can typically be found in Appendix A of the instruction manual.