The Krown Phone Flasher, model K-PF200, is a flashing light telephone signal designed for use by individuals with hearing disabilities. The unit attaches to any modular phone jack. Its 180 degree dome cover spreads an ultra bright LED signal throughout the room to alert the user of an incoming call. It also works with most PBX systems and video phone equipment. POWER: Uses power from phone line. WEIGHT: 1 pound. WARRANTY: 1 year limited warranty.