This includes the licence-free band of 863 to 865 MHz.

These antennas are usually described as "Half-Wave" but examination of the internal construction reveals that they are a little more than that. They are actually half-wave dipoles.

The antennas (antennae?) often supplied with low cost radio microphone receivers are usually 1/4 wave rods. I.e. a simple metal rod about 80 mm long for the 800 MHz region. 

The antennas offered here are twice as long (half-wave) and, being dipoles, they give greater gain in the direction perpendicular to the antenna. They should therefore give more reliable reception.