All I can say is it wow! This Inverter runs with out the hum that the X brand I had did. Thanks for the service Marcello!
Excellent product on it's own, very reliable and few complaints. HOWEVER if you arrange the inverters in a horizontal orientation and stack them vertically like in the Flexpower Two arrangement, you will have problems with the top inverter overheating if you try and produce maximum rated power at nearly any ambient temperature, ESPECIALLY if you leave the shrouds on them. Removing the shroud (the concave piece of aluminum that covers the front) will solve your overheating problems for a single inverter, but with two you will be unable to maintain full power production. If your solar array can produce enough power to max these puppies out, you will need to arrange some kind of secondary cooling, which in our case was achieved with 38 watt AC fans controlled by the auxiliary control built into the inverter. So at least it has the ability to solve it's own problem.