This is one of the lightest and slimmest antennas on the market - Suitable for the 900 MHz ISM band. It is designed to operate in free space, or stuck onto a relatively RF transparent material, eg. Foam wing, fuselage, balsa wing, thin fiberglass. It has better than -10dB return loss when in free space or mounted on foam or balsa. This antenna is designed to be vertically polarized when mounted vertically. For example, when mounted on a vertical stabilizer of an aircraft, it will radiate the same as a vertically mounted dipole.