Core Features: Seamless Handover And Roaming Up To 250 Parallel Calls / 60 Bases / 250 Handsets / 250 Sip Accounts Support Ldap / Remote Phonebook / Xsi Directory External Antennas Coverage Up To 50M Indoors And 300M Outdoors Cat-Iq 2.0 Dect / Opus Codec Compatible With Yealink W59R/W56H/W53H/Cp930W/Dd Poe (No Psu Included) Dect Manger: For Use With W90B