The Wilson's 301111 outside Yagi is a directional antenna that improves signal transmission between your Wilson amplifier and your nearest cellular signal tower and features up to 13 dB of gain. It is designed for fixed installations and must be pointed to the nearest cellular signal tower.
NOTE: Yagi antennas will only work in straight land and line of sight situations. They will not work in mountainous areas, since they have to be pointed towards the cell tower on a straight line without anything else in the middle.