The firmware is locked to the serial numbers hard coded in the firmware itself, not just model numbers.It was in limited beta assigned based on the model number of the pager to those who originally signed up, and is no longer available. Unication appears to have stopped support for it.
Also, it wasn't a "scanner" like we're all used to where you tell it to watch systems A, B, and C. You would put in a frequency range and it would scan through it to find activity that way. It was a really terrible implementation and I ended up selling my G5.