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Amazboost A1 Cell Phone Booster - Up to 2,500 sq ft.

MULTI-USER — Instantly improve cell signal of talk, text, and data for multiple users and cellular devices, resulting in fewer dropped calls, better voice quality, faster data speeds, and more
FOR HOME ROOM — Max gain 60dB , Amazboost A1 improves cell coverage in a large room, like a home office, studio apartment, or living room
5G READY — All Amazboost products support the latest in 5G technology, working seamlessly within a 5G network to deliver the best cell signal possible
FCC APPROVED — The booster is compliant with the requirements of the standards applied. FCC authentication certificate ID:A7V-SR75702001,HVIN:TRUE5-D.Approved to operate without interrupting or harming any cell carriers' signals to and from the cell tower.

First, make sure you can get at least 1 bars outside, then signal can be boosted indoors. Note: If there is no signal outside, then it may not work.

Make sure your outdoor antenna directly faces to the signal tower. It can maximumly capture all.

Indoor antenna can boost signal captured by outside antenna. Make sure the indoor antenna is away from heat and liquid.