Overall internal parts are high grade, its assembly is poor though. Better ones like this https://amzn.to/2LMbz9S by Power TechOn have modern all automated construction. I have installed numerous Power TechOn on solar jobs without any fails, but trying a new brand got me this PUGU inverter in the video. PowerTechOn is the same as a VertaMax product, at a lower cost. SEE VIDEO 1 also! https://youtu.be/zavAGHukOYY