I was thinking it was just a beefed up version of the same. I have one of those OK4U/Microsine inverters, of the original Trace branding, but have never used it. The hurdles of getting approval for such a small inverter are just too great for me to justify. I have not even bothered to grid tie my larger Trace. At the time I looked into it the engineering certification of the installation and inspection process seem to me to be designed to prevent any installations other than by one utility approved company here. Given the likely return on investment for such a small unit, just doesn't seem worth all of the hurdles and hassles. Rich