zBoost YX-510 Cell Phone Signal Booster Dual-Band Unit for Home or Office Extends cellular coverage for single or multiple users in homes or offices--provides up to 2500 square feet of coverage Dual-band device works with 800/1900 MHz frequencies from all major carriers--AT&T, Sprint, T-Mobile, Verizon, Alltel, Cricket, and more (not compatible with Nextel) Omni-directional signal antenna receives signals from multiple cell towers Antenna can be installed outdoors above the roofline or indoors in the attic or near a window Extends phone battery life--uses less power when signal is stronger