The Yealink W73P DECT handset supports up to 10 SIP accounts and 20 simultaneous calls. It's compatible with the Yealink W70B base station.
 
Key Features:
High-performance SIP cordless phone system 
1.8" 128 x 160 TFT color screen with intuitive user interface 
Up to 20 simultaneous calls
Up to 10 DECT cordless handsets 
Up to 10 SIP accounts
Support Opus audio codec 
Noise Reduction System 
FNR (Flexible Noise Reduction) 
Up to 35-hour talk time (in ideal conditions)
Up to 400-hour standby time (in ideal conditions) 
Quick charging: 10-min charge time for 2-hour talk time 
TLS and SRTP security encryption 
Headset connection via 3.5 mm jack 
Charger wall mountable
 
Datasheet