The Cell Phone Signal Booster supports GSM900 ，it works with GSM/EGSM 900MHz 2G network，it supports any wireless operator in the frequency range of 890 ~ 915MHz and 935 ~ 960MHz. It could only strengthen cell phone signal， could not produce cell phone signal，if there is no cell phone signal at all in your area，there is no need to use it.Specification:Frequency range : 890MHz--915MHz(Up link) 935MHz--960MHz(Down link)Power: -70 ~-40 dBm/ FA (1.23MHz)Gain : Uplink 50/55/60/65Db/±10DB Donwlink 55/60/65/70Db±10DBSignal coverage : Up to cover for 150-200 square meters useImpedance : 50Ω Seclusion : >65 db Power supply : AC110/220V(Used AC/DC Adapter 12V DC)Compact design: Indoor useItem dimension : 105 x 85 x 20 mm Package:1 x Aluminium LCD DISPLAY GSM 900 cellphone repeater 1 x Omni direction outdoor antenna with 10 meters cable1 x Indoor antenna1 x Charger 1 x User manuall