Outback FX and VFX Sine Inverter/Chargers – (1.3kw – 30kw) Outback makes only pure sine wave inverter/chargers in sealed and vented configurations from 1.3kw and 3kw. Up to 10 Outback inverters can be stacked in parallel and three phase for power output as high as 30kw. The sealed units are great for corrosive or wet environments. The vented units are identical inside, but ventilation allows them to produce approximately 50% more power. The latest addition to the line is the 1300w GFX, which has all the VFX functions but a more attractive price point. Outback manufactures in the USA and is owned by former Trace Engineering staff.