These are certainly one of the better tuning machines. They turn smoothly and don't have much wobble. They're made by Grover, presumably in Korea, and will retrofit Grover Rotomatics without drilling any additional holes. However, build quality could be improved as there are casting marks on the housings and the plating isn't perfect. They're good tuners for the price but if you're searching for the perfect tuning machines, I would suggest taking a look at Schaller instead. They make a version that looks the same and is available with similar tulip-shaped buttons. They are smoother to turn, have less wobble and the plating is of a much higher standard.