Each size of the Series RN-RO-RV of hollow output shaft speed reducers is designed with a common base body that gives rise to three different speed reducer lines by the means of the appropriate input module fitting: RN shaft mount, RO horizontal and RV vertical input bevel/helical. Speed reducers are designed in six sizes - aluminium pressure die cast for the smallest three and grey cast iron for the bigger ones - with 30 reduction ratios in two and three stages, and output torques from 180 to 3200Nm.