Increases range over the standard rubber antenna supplied with the Astro/Alpha. Some customers have reported up to a 50% increase in range. I will not claim that much added range but it will out perform your stock antenna and in some cases the folding antennas. Antenna is made to withstand abuse and it measures 14". 14 inches tall Felxible Increases range over the standard rubber antenna supplied with the Garmin Astro/Alpha Up to a 50% increase in range