Circular Wireless HELIAXIAL58 Helical Axial Mode 5.8 GHz FPV Antenna Specs: Right Hand Circular Polarized (RHCP) directional antenna with high gain, ideal for use on a video receiver for long range FPV. Minimum of 12dB of gain, and combined with a Skew Planar Wheel Antenna on the video transmitter offers over 6 km of FPV range. Adaptor: Supplied with an SMA female connector, and includes three adapters, allowing different ways of connecting the antenna to the receiver at any angle. Construction: The reflector is 3mm aluminum, the support structure is Plexiglas and the helix is enameled copper. The start of the helix runs parallel to the reflector. This is the impedance matching, and it has been adjusted manually for each individual antenna. Bandwidth: Huge bandwidth, see chart. A Return Loss of 95% of the power is coupled to the antenna. Gain: 12.33dB, with a beamwidth of about 60 degrees. Avoids multipath interference with greater than 10dB crosspolar signal attenuation in all cases. This helps to avoid broken up video due to reflected signal from cliffs, buildings, etc.