The BMS is the best choice when mounting a monopole style antenna to a vehicle as it mounts the antenna very close to the ground plane ensuring the very best SWR and radiation pattern, this is especially important with regards to UHF antennas such as S474, M474, M475, M476 etc as mounting these antennas onto z brackets can cause a poor SWR due to the raising of the antenna too high over the bonnet. The powder coated black will fit most vehicles bonnets and boots. The BMS is strong and efficient, simple to use, secure, no drilling holes and is quick to remove with an allen key.