The Wilson 462075 Enterprise 4330 Kit Wireless Signal Boosters is a commercial-grade, in-building cellular signal amplifier from the WilsonPro Enterprise/Pro line, the same family of bidirectional boosters used to extend carrier coverage through steel, concrete, and low-reception buildings. Like other units in this line it's designed for professional installation, pairing an outside donor antenna with an inside distribution antenna over low-loss coax to rebroadcast a stronger signal indoors.