Cell phone signal boosters (also known as cell phone repeaters) were developed to address the two factors that cause poor cell phone reception. They're designed to amplify a weak outside signal and bypass any obstructions to provide a strong inside signal to an area that was originally .lacking. Single Band Booster Cell phone becomes especially helpful when people get into critical situations. In case of emergency a timely call can save a life. Unfortunately, there are still some places where one can find themselves - out of coverage. Usually those places are either too far from the cell phone base station or located inside underground constructions, for example: parking lots, tunnels, big stores, office buildings, cars, boats, house in remote areas, etc. Features:1. High-gain linear power amplifier.2. ALC and AGC function technology. 3. Ultra-low noise receive amplifier. 4. There is no interference to the base station, right after the opening of the original system and the base station without the need to adjust parameters.