The Taoglas MMB.A.EXTMA.16 is a robust magnetic mount base solution for external Taoglas antennas that would typically require drilling a hole for installation. There are times when drilling a hole for installation is not feasible either due to cost or aesthetics. The magnetic mount base removes the need to drill by providing an adapter with the proper hole size for the antenna you are using. This bracket supports the Taoglas Olymian Series Antennas, (G30 and MA140). It can be mounted on iron/steel metal surfaces such as tops of vehicles, containers, etc. Due to six strong magnets, the magnetic force can resist wind speeds over 100 KM/H (road test). There is a soft cushion of foam which can protect the mounting surface during the mounting/removing processes. The aligning hole diameter for the MMB.A.EXTMA.16 is 16 mm. It comes assembled making it ready for installation.