Hello, http://www.powerequipmentdirect.com/Reliance-Controls-GPK30RV/p1893.html Reliance Controls Sidewinder™ Parallel Power RV Cables is an example of this. That one is universal. Honda makes same thing for their invertor generators, plug two 2,000 watt together to get 4,000 watts. Intriguing. Looking at picture at that site, it looks like $99 for wiring two to one. No box. Just a plug. I have posted on dilemma of 800 watt inverter (earthquake brand) that is super light and quiet but trips on 780 watt drill on startup. Am now planning on getting second one (inv/gen) and did get smaller drill. But if can hook two of these cheap 21 pound quiet gens together, wow would have 1600 watts that would cover all our power tools. What do the experts think here? Is that link http://www.powerequipmentdirect.com/Reliance-Controls-GPK30RV/p1893.html just wires we can do ourselves, or do those have some sine wave matching circuit in them?