Support Unit. Mobile platform that causes damage to alien nearby units.
The discovery that certain ultrasonic frequencies were highly repulsive to indigenous wildlife was made shortly after planetfall, which in turn made the Ultrasonic Fence possible, leading to improved settler mortality rates and greatly improved safety for colonists. Enterprising engineers turned towards making smaller-scale models with higher-frequency modulations that could cause physiological damage in the indigenous wildlife after prolonged exposure. Some factions achieved success in designing portable modules, although only the immense trade caravans and ships had on-board generators with enough power to reliably support them. A few early portable designs proved to have a catastrophic flaw, interacting with planetary mineral geology to create resonances that actually attracted hostile wildlife. Of these, the ARC Planeteering Model 8 is the most notorious, quickly gaining the nickname "Model Ate."
Interestingly, the most comprehensive breakthroughs in small-scale ultrasonic emitters were made by survivalists living on the margins of the major factions. Often these clans of homesteaders would build their own home-made ultrasonic palisades through reclaimed and repurposed technology and an impressively dedicated process of trial and error. A meta-ethno-engineering survey of these ultrasonic palisades made in the 2C post-fall discovered that these groups had arrived independently at an effective design a number of times. Their work led to the design of the first dedicated, reliable, and portable Ultrasonic Emitter vehicles, though few of the clans either know, nor seem to express much appreciation of the technology that allows the expansion of society into territory they previously considered the property of themselves and the wildlife.