Directional antennas are a must-have in any comms toolkit.
 
A Yagi-Uda antenna (Yagi for short) is a common type of directional antenna. It consists of a driven element, a reflector, and one or more director elements. These effect the antennas radiation pattern, causing it to radiate more RF energy at the front of the antenna than at the sides or back (this also affects received signals.)
 
Being able to direct the RF radiation pattern of your antenna is extremely important. It allows for your signal to not only travel farther, but greatly decreses the risk of detection. You can also use these antennas for rudimentary direction finding applications, by measuring the recieved signal strenght at different bearings and locations, then overlaying them on a map. 
 
This is a 3 element Yagi that can fold up, making it more convient for field use than traditional fixed antennas. 
 
This antenna comes with mounting brackets.
 
Frequency Range - 400~470 MHz
Bandwidth - 20MHz
Impedance - 50Ω
VSWR - ＜1.5
Gain - 7 dBi
Polarization - Vertical
Horizontal 3dB Beam Width - 53°
Vertical 3dB Beam Width - 45°
Front To Back Ratio - >15 dB
Maximum Power Input-watts - 100W
Lighting Protection - Direct Ground
Connector - SL16.K