The build quality is what you'd expect with an import part like this. Not the best, but should work. The real problem is with assembly. Obviously whoever is putting these together has no concept of what a needle valve is! They screw them down so tight that they ruin them. When I unscrewed the low speed needle, it was wedged into the pressed in brass jet so tight that it came out with the needle! Same thing with the high speed needle! I cleaned everything up, pressed the jet back in, sanded the grooves out of the needles and I'm hoping for the best. Pay more and buy a better one.