ATT Cell Phone Antenna Booster for Home GSM 3G 4G LTE Band 2/5/12/17 AT&T T-Mobile U.S. Cellular Cricket Cell Phone Signal Booster Boost Voice and Data Cover Up to 4,000 Sq Ft

●Warm Reminder: Cell phone antenna signal booster can only amplify signal but it can’t create signal. Please make sure you get 2 bars signal outside, it won’t work if there is no signal existing. This cell phone booster boosts for multiple cellular devices simultaneously, supports band 2/5/12/17, please confirm if your cellphone band is covered by the booster before purchase. ● How It Works: Cell phone signal booster increase cell signal by collecting signals with a powerful antenna, delivering those signals to the booster, amplifying the cell signals so your devices receive them, and delivering your device’s boosted signals back to the cell tower. 1. Receives Signal- The outside antenna reaches out to the cell tower to access voice and data signals. 2. Transmits Signal- The booster receives the outside signal from the outside antenna. 3. Boosts Signal- The booster amplifies the outside signal and sends it to the inside antenna. 4. Expands Signal- The inside antenna broadcasts the boosted signal to devices inside the home.