Yealink W80B Base Station With Seamless Handover And Roaming, Up To 100 Parallel Calls, Up To 30 Base Stations, Up To 100 Handsets, Up To 100 Sip Accounts, Support Ldap/Remote Phonebook, Support Xsi Directory, Dect Radio Coverage Up To 50M Indoors And 300M Outdoors, Support Poe, Compatible With Yealink W56H/W53H, Support Opus, Power Adapter (Optional).