These Inline Helical Gear Reducers units are built to German Institute for Standardization (DIN) specifications. Available in 5:1 to 120:1 ratios and Box sizes 37 to 147, horsepower range from 1/4 HP to 75 HP, and designed for high efficiency, high strength and low noise. All cast iron housings for unquestioned strength and reliability and gears are precision processed for better rotation and quieter operation. Gearbox flanges are designed to except NEMA C-face electric motors so there is no coupling necessary. They drop-in for most major European-produced inline reducer brands and have a 2 year warranty.