A revolutionary cell phone signal booster for demanding professional coverage applications, the zBoost designed YX645, for custom installers, is a Bi-Directional Amplifier (BDA) System which captures and amplifies the cell signal. The use of radio distribution equipment that enhances, extends or amplifies a wireless signal may be prohibited without the consent of the wireless carrier upon whose network such equipment will be used. You should consult with your carrier before purchasing such equipment to use with that carrier’s service.