Vktech GSM 900MHz Mobile Phone Signal Repeater Booster Amplifier + Antenna Kit The repeater works with two antennas (included in the kit) One is the indoor antenna which communicates with your cell phone or laptop data card, and another one is the outdoor antenna which communicates with the cell tower The miniature repeater is mainly used in office buildings, shop-ping malls, large underground parking field, exhibition center, workshop Frequency Range: Uplink 890-915MHz; Downlink 930-960MHz Connector : N female connector