zBoost ZB545 SOHO Dual Band Cell Phone Signal Booster for Home and Office, up to 2,500 sq. ft. Extends cellular coverage for single or multiple users in homes or offices--provides up to 3000 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 Frequency:1850 to 1990 MHz. Operating Conditions : 40- 105 Fahrenheit Extends cellular coverage for single or multiple users in homes or offices--provides up to 2500 square feet of coverage. NOTE - There should be a minimum of 15 vertical feet of separation between the Base Unit and External Antenna. 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 Antenna can be installed outdoors above the roofline or indoors in the attic or near a window Ideal for small homes that have reliable outside signal Reduces dropped and missed calls and provides faster 3G data performance for multiple simultaneous users Automatically operates at maximum gain  no manual adjustments needed