We, H-Fang, are the world leading professional manufacturer for slewing drives along with slewing rings. There are more than 10 different sizes, starting from 3' size to 25" inch size, among them are 5", 7", 9" 12", 14", 17", 19" and 21". They are both widely used in solar tracking systems (PV, CPV, HCPV and heliostat) and regular vehicles, such as manlifts, truck cranes, as well as modular vehicles. We are the first manufacturer in China who registered the product standard, which will be accepted as National Standard for slewing drives very soon.