CEL-FI RS225 3G/4G up to 42 Mbps HIGH SPEED DATA Reduce Dropped Calls and Dead Zones. All you NEED is 1 BAR TO GET 5!! Easy to Install-True Plug and Play, Self-Configuring, No external Antennae or Cabling needed. Professional installation Not required! Cel-Fi is the ONLY Cellular Signal Booster Authorized for use on the AT&T Network and Approved by the FCC for 100dB Gain-Providing a LARGER Coverage Area and 1000 Times Greater Gain than current analog boosters The Cel-Fi All Digital Booster can Cover up to 13,000 sq. ft., making it IDEAL for Homes and Offices and Each Cel-Fi system can SUPPORT up to 60 Concurrent Users All Digital Simultaneous Voice and Data (AT&T Dual Band 3G and 4G HSPA+ on 3GPP band 2 & band 5) with Peace of Mind Guarantee: 30 Day Return policy and 2 Year Product Warranty