In the link, you can go to Specification and find the information below. So there are two PA4020P and one PA4010P in the kit. To find out the correct model number of a single unit, you can check the back of it. The lable on device itself shows such information. By the way, why do you want to upgrade the firmware? Any problems there?
Accessories included
- TL-PA4010P
- TL-PA4020PKIT
- RJ-45 Ethernet cable (2 m)
- Quick Installation Guide
- Resource CD

Thanks M Diamond. Right, I have the model numbers. The only reason for the upgrade was thinking 'latest = greatest'. But only one model has a newer version and the release notes don't convince me it is worth ("if it ain't broke...").

If no problems with them, no need to ugprade, lol... Once upgrade, you may have to re-pair them and do more extra work. :rolleyes: