This refurbished KX-TGA420B is a 4-line deskset extension of the KX-TG4000B or KX-TG2000B base units. The maximum range for the KX-TGA420B is 150 yards (going between two walls) but the optimal performance maximum distance for this deskset is no more than 100 yards.It can only be used with the Panasonic KX-TG4000B and KX-TG2000B Cordless Phone Systems. Features: – 2.4GHz Corded / Cordless Desk Extension – Digital FHSS Technology – 2-4 Line Operation – Caller ID / Call Waiting – Digital Duplex Speakerphone – 3-Line Backlit LCD Display – 30 Station Name / Number Caller ID Memory – 50 Station Phone Directory / Dialer – 3-Way Conferencing – Adjustable Ringer Volume Control – Automatic Intercom – Call Transfer – 2-Way Paging – 94-Channel Frequency Hopping – Redial – Hold – Flash – Navigator Key – Up To 8 Hours Talk Time – Up To 96 Hours Standby – 2.5mm Headset Jack The station unit KX-TGA420B is one of the stations (extensions) of the KX-TGA4000B/KX-TG2000B base unit, the same as the cordless handsets*. A maximum of 8 stations in any combination of the station units and the cordless handsets can be installed to the base unit ( the first station will be the handset included with the base unit). *The handset is included with the base unit and is also the optional cordless handset KX-TGA400B/KX-TGA200B.