This is the portable cell signal booster that improves reception to prevent dropped or garbled calls when driving. Counteracting dead zones and signal interference caused by obstacles such as mountains, trees, and skyscrapers, the patented device has been shown to produce an average cell signal gain of 300%. In real-life tests by The Hammacher Schlemmer Institute, the booster enabled phone conversations through a dead zone to continue uninterrupted when previously they had been dropped. The compact, cordless booster tucks into a pocket that slips over a car’s visor and can be carried with you at all times. Because it requires no cables, batteries, or power it’s always working to keep you connected. Made in the U.S. Black/Gray. 12" L x 7" W x 1/4" D. (1 lb.)