Cel-Fi PRO improves 3G, 4G, and LTE cellular service by eliminating dead zones and dropped calls. With 100 dB of gain, Cel-Fi PRO will not only improve cellular service across four (4) concurrent bands, it will also reduce your cell phones power requirements and extend its battery life. Cel-Fi PRO covers up to 13,000 ft2 (1,200 m2) of indoor space per system. Cel-Fi PRO systems feature an LCD color interface, are fully self-contained and self-configuring, and require no external antennas or wiring. Simply plug it in to boost indoor cellular coverage. Cel-Fi PRO EXA variants feature an external antenna connector to enable the use of an external Donor antenna. A Cel-Fi PRO EXA with an external Donor antenna can thereby acquire an outside signal, allowing it to be used in applications where no signal is present indoors (i.e. cement, metal walls, etc.). This opens up new opportunities for using Cel-Fi PRO Smart Boosters when other solutions fail. Cel-Fi PRO EXA enables cellular coverage in hard to reach places by allowing the Cel-Fi Network Unit to be placed, where no service exists.