MenaceRC Viper is a directional antenna with high gain and linear polarization. Small rod antennas with linear polarization are used mainly on Whoops and on small 2-3 " copters.
When combining antennas with circular polarization on the glasses and linear polarization on the copter, 3dB is lost, which corresponds to the video transmitter transmitting at half power. Thanks to this antenna, you will prevent these losses and increase the range of the video.