The VTech 17850 allows you to connect up to 2 mobile phones to make and receive mobile calls. This allows calls to be made using either your home line or mobile network from any VTech 17550 handset. You can use the MobileConnect to transfer contacts from your paired mobile phones to your VTech 17850 up to 1500 entries in total. Lets you make calls during a mains power interruption with your cordless phone. During a mains power interruption you can supply the power stored in your handset battery to the base unit, so you can make calls even when the power is out. Long range is delivered through a state of the art DECT system that includes a unique antenna and software design together with advanced noise filtering technology.