Quick overview from the supplier:
Grandstream GXP1620, 2 SIP,2 Line, no PoE, Black
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2 SIP accounts, 2 line keys, 3-way conferencing, 3 XML programmable context-sensitive soft keys
Dual-switched 10/100 mbps ports
HD audio on speakerphone and handset
EHS support for Plantronics headsets
Up to 1000 contacts, call history up to 200 records
https://www.grandstream.com/products/ip-voice-telephony-gxp-series-ip-phones/gxp-series-basic-ip-phones/product/gxp1620/gxp1625
