Question about Loronix recorders

[bigkid52 0]

I'm working on a site with Loronix recorders, probably 5-6 years old.

The software is 4.5.1

 

I have what I think is the serial number for each unit written on the back, but when I reinstall the software, it's not a valid number.

Is there a prefix or suffix I should be using with the 5 digit number?

 

Thanks

Bob