The A4VSO is a swashplate-type axial piston variable pump designed for efficient hydrostatic drives in open circuits. Its notable features include excellent suction characteristics, low noise levels, long service life, high power-to-weight ratio, and a modular design. It offers a wide range of displacement sizes, from 40 to 1000 ml/rev, and can handle nominal pressures up to 350 bar with peak pressures reaching 400-420 bar.

These pumps are widely used in heavy-duty industrial applications such as ceramic presses, refractory material presses, steel and forging equipment, metallurgical machinery, mining machinery, marine machinery, petroleum equipment, engineering machinery, and machine tool control systems.