This is the smartphone dock with built-in LEDs and a ring amplifier to ensure you never miss a call, text, or message. Without requiring a complicated network configuration or cable hook-up, its loud 87 dB ring and four flashing LEDs are activated when a smartphone vibrates. If a call or message is missed, the light continues to flicker until the phone has been checked and the dock has been reset. With a USB port that allows it to function as a power dock using an existing charging cable. Also works with a landline via an integrated telephone jack as well as with Skype and Facetime calls. AC plug with battery backup (requires four AA batteries). 4 1/2" L x 4 1/2" W x 3" H. (8 oz.)