Dr Tech 3 in 1 Combo Cell Phone Wireless Signal Booster for Home or Office , For Verizon 2G 3G 4G ; AT&T 2G 3G ; T-Mobile 2G ; T-Mobile (MetroPCS) 2G ; Sprint 3G 4G ; U.S Cellular 2G ; 700MHz & 850MHz & 1900MHz ALC ensure output level stable and adjustable continuously. Low power consumption and avoid to interference to BTS. LED indicate and judge to signal level of uplink and downlink. With the amplified linear power, the intermodulation and and spuriousness are suppressed effectively. To easy or and convenient installation.