1 Handset System: 2 landlines and Link-to-Cell via Bluetooth allow for up to 3-Line simultaneous communication The 2-line answering system can be used separately for ordinary contacts and emergency contacts Powerful battery backup system keeps you connected in the event of a power outage Call blocking function lets you easily block up to 250 telephone numbers Noise Reduction automatically suppresses background interference while enhancing voice tones so you can easily hear conversations