Connectivity technology: RJ11. "2" WHITE BACKLIT DISPLAY - high-contrast text on the extra-large 2" screen makes it easy to read incoming caller id or call history records. plus, the white back lighted handset keypad allows for easy dialing in low-light conditions.". BLUETOOTH CONNECT TO CELL - Make and receive calls from your cellular plan while enjoying the comforts of a home phone. Pair up to 2 cell phones and connect 2 cell phones, or one cell phone and one BLUETOOTH headset for use with landline calls. With a touch of a button, enjoy the high-tech benefits your smart phone offers. Even if your smart phone is in a different room, you can still access Siri or Google Now from the cordless handsets. Place a call, listen to a text message, respond to a text message with a voice respose and perform all the other actions these services offer. SMART CALL BLOCKER AND CALLER ID ANNOUNCE - this system lets you block nuisance callers on the spot with one touch. you can permanently blacklist up to 1,000 numbers. what's more, it can filter robocalls and unwanted call while allowing welcome calls to get through. for screen out robocalls, set it to ask the callers to press the pound key. for screen out unknown callers, set it to ask the callers to record their names and press the pound key. after your caller completes the request, the phone rings and announces the caller's name. you then can choose to block or answer the call, or forward the call to the answering system. SUPER LONG RANGE UP TO 2300 FEET - experience the best in long-range coverage and clarity, provided by a unique antenna design and advances in noise-filtering technology. with over 2000 feet or range, you can be on a call anywhere in your home, yard, or even your neighbors home. ACCESSORY HANDSET ONLY - requires a IS8151 series phone to operate. each IS8151 can support up to 12 handsets. additional handsets can be placed anywhere in your home or office where you have an electrical outlet and do not require a phone jack. convenient, flexible, and easy to use.