Designed for buildings up to 20,000 sq ft- the SureCall Fusion5X increases voice, text and 4G LTE signals for 20+ simultaneous users on all carriers in North America, including AT&T, Verizon, Sprint and T-Mobile. Configurable for all indoor environments, the Fusion5X reduces dropped & missed calls and improves 4G LTE data speeds to ensure everyone has a reliable connection to their mobile device. The Fusion5X booster features sturdy metal construction and an industry leading 3-year warranty. Fusion5X doesn''t feature attenuation knobs, instead, sophisticated software automatically and continually optimizes gain ensuring the booster is always operating at maximum performance. Fusion5X kits include (4) internal antennas which provide the flexibility to customize your installation to meet the needs of any large building or challenging floor plan.