High-Definition Sound Technology makes even the weakest voice sharp, clear and easily audible, a new standard in speech amplified telephone technology Amplifies the out-going voice up to 40dB Can be easily set to ampligy the incoming sound up to 18dB Latest Digital Sound Processing technology eliminates virtually all distortion, echo effects and unwanted static commonly found in other ordinary amplified phones 9 easy to use photo-memory buttons for one-touch dialing Two (front and side) visual ring flashers that flash when the phone rings 95dB+ super loud ringer with adjustable ringing volume and tone controls Battery back up for power outages (batteries not included) Hearing aid compatibility One year warranty