zBoost YX500-l Cell Phone Signal Booster up to 2500 Square Feet of Coverage for Home or Office (800 MHz Phones) Extends cellular coverage for single or multiple users in homes or offices--provides up to 2500 square feet of coverage Works with AT&T, Verizon and Alltel cellular wireless phones in the frequency range of 824-894 MHz 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