Vtech VCS754 ErisStation Conference Phone with 4 Wireless Microphones VoIP and Device SIP conference phone, Includes 2 fixed microphones and 4 DECT 6.0 wireless microphones with Orbit link Wireless Technology, Two-year warranty Central full-duplex speakerphone in base, Supports up to three SIP lines/accounts, G.722 codec support for HD audio, USB connection for using a PC based softphone or speaker. DECT 6.0 wireless microphones with Orbit link Wireless Technology, 3-way local conference, Local phonebook up to 200 entries. Requires SIP phone line / Device is not analog, Up to 8 hours of talk time per wireless microphone and up to 70 hours of standby time per wireless microphone