Full duplex speakerphone delivers superior sound quality & clarity. Two line operation with Auto Line Select automatically connects users to ringing or open lines. Compatible with most headsets (via 2.5mm jack) & hearing aids. Base model plus Bluetooth ® compatibility lets users make & receive cell phone calls as well as conference calls between cell phones & landlines. Lines: 2; Telephone Type: Corded; Caller ID / Type: Standard Display; Speakerphone: Base.