One KX-T0155 provides 2-channels for Panasonic handsets. This means each cell station can only handle up to 2 simultaneous phone calls. For systems with multiple handsets, we recommend adding addtional cell stations for improved performance when answering calls. KX-T0155 cell stations must be positioned 10 feet apart or more otherwise cell stations can interfere with each other (think of it as the handset doesn't know which cell station to communicate with and bounces the signal repeatedly between stations). In most scenarios, cell stations are placed approx 75 feet from each other, creating overlapping cell coverage. One cell station KX-T0155 has approx 150 feet in radius coverage

Please note, the limiting factor of 2 phone calls per station. For example, if you have 4 handsets and 1 cell station, only 2 phones will ring on an incoming call. The 3rd and 4th handset will say "Cell Station Busy". If you experience this frequently, add another cell station approx 20 feet away.

The KX-TD7685 will work with the KX-TAW848 and KX-TDA series phone systems (version 3.0 or later), and the KX-TDE 100/200 (version 1.0 or later). The KX-TD7685 ONLY works with the KX-T0155 and KX-T0158 Cell Stations. This system cordless phone requires a Panasonic Key System Unit with cell site functions only available on KX-TAW848, KX-TDA50 , KX-TDA100, KX-TDA200 , KX-TDA600, KX-TDE 100/200, and the KX-NCP Phone Systems. It will not work standalone. Please contact us if you have any questions regarding compatibility with your system.