Yealink SIP T42U. Product type: IP Phone. Product colour: Grey. Handset type: Wireless handset. Phonebook capacity: 1000 entries. Display: LCD. Display diagonal: 6.86 cm (2.7"). Display resolution: 192 x 68 pixels. Ethernet LAN interface type: Gigabit Ethernet. Supported network protocols: IPv4/IPv6. SIP v1 (RFC2543). v2 (RFC3261). UDP/TCP/DNS-SRV (RFC 3263). Security algorithms: 256-bit AES. HTTPS. TLS. WPA2. WPA3. AC adapter input voltage: 100 - 240 V. Input frequency: 50/60 Hz. AC adapter output voltage: 5 V