These are 3dBd gain omnidirectional collinear antennas characterised by broad operating bandwidths making them suitable for single frequency or duplex applications.

The COL11 is electrically identical to the COL7 antenna (although it does feature an up-rated stub design for additional power handling capabilities). The ruggedised radome which houses the active elements of the COL11 was originally designed to serve as the mast of recreational sail boards and is immensely strong. The radome is coloured black to maximise solar heat retention and this has been shown to aid significantly in ice shedding. A large, 60mm diameter alodined aluminium mounting tube supports the radome.