I was noticing that too and I had no clue what unlocked meant. Take a look here - https://community.linksys.com/t5/VoIP-Adapters/Is-my-PAP2T-unlocked-difference-between-PAP2T-amp-PAP2T-NA/td-p/217067. Seems that unlocked means it isn't password protected or controlled by a VOIP provider. And my guess is that marketing group think took over, which is why every eBay post seems to state "Unlocked".