This is the second SUNGOLDPOWER solar inverter/charger that I have purchased. I would purchase a third unit if I have another application. These units are very compact compared to competitors' units such as those from OUTBACK POWER (I own one of those too). The unit is easy to connect, quiet, and has an easy-to-read display for monitoring operation. I have been impressed by the technical response from SUNGOLDPOWER which has promptly answered my questions and send explanatory photographs of internal circuitry.My unit came with some cosmetic damage where a fork lift apparently crushed the edge of the case and some separately-bagged DC insulators (but there was no damage to the very well packaged unit, so the damage occurred prior to shipping). SUNGOLDPOWER promptly replied to my query about this stating: "Yes, the deformed part looks like it was forked by a forklift. Our other models of inverters (packed in cartons) are sometimes deformed when the forklift forked the inverter shell during loading and unloading. Because the machine is very heavy, when it is packed in the factory, it is basically packed by machinery and automation. Generally, this kind of damage will not occur. We are also working hard to analyze and find the reason to avoid similar problems next time. install and test the unit first to see if there is any problem with its function. If there is no problem, I will apply to the company for some compensation." I was very impressed by this response, explaining how the damage could have occurred and that SUNGOLDPOWER would consider some compensation for the damage. The really great news is that the unit passed all of my electrical tests, so the slight damage to the case is only cosmetic.Summary: A+ for design; A+ for customer service; A+ for operation.