MIMO communication systems are needed in high speed wireless applications. A MIMO (Multiple-Input-Multiple-Output) system uses at least two antenna structures and is more advantageous than single-input single-output (SISO) by increasing channel capacity and reducing transmitting power. MIMO antennas should have compact structure, high radiation efficiency, low envelope correlation, and high isolation between the signal ports. In small structures (antennas spaced closely), the application of MIMO technology has been restricted by high degree of coupling and spatial correlation between antenna elements due to the limited available space. The isolation between antennas become critical as it can deteriorate the system performance and decreases channel capacity. Taoglas have designed the Hercules MA515 antenna to meet these demanding requirements The Hercules MA515 MIMO 2.4GHz 3dBi antenna is low profile, heavy-duty, fully IP67 and IP69K waterproof external M2M antenna for use, transportation and remote monitoring applications. This unique omni-directional 3dBi antenna provide high efficiency and high isolation (>20dB), between antennas elements in a heavy-duty low profile compact structure, delivering powerful MIMO antenna technology for Wi-Fi 802.11n. The antenna screws down permanently onto a roof or metal panel and can be pole or wall-mounted. The two antenna elements are vertically polarized, matching well with the polarization of most wireless routers antennas. An envelope correlation co-efficiency of only 0.2 ensures good performance with the MIMO module. For industries such as remote monitoring, smart meter systems, construction equipment, public safety at only 29mm high, the Hercules MA515 MIMO antenna provides an unobtrusive, robust, rugged antenna that is durable even in extreme environments.