A hydrostatic system for step less rotary movement transmission having two hydrostatic motors with radial pistons connected in a push-pull configuration, an oil distribution system and a system for elimination of air and other volatile substances from the working spaces. The input of the gear box is connected to the engine and the output is connected to the external load. In this push-pull configuration of both hydrostatic motors, the stators of both hydrostatic motors are the active part of the gear box, while rotors of both hydrostatic motors are the passive part of the system. Additionally, the hydrostatic system has both hydrostatic motors having the same rotary speed but moving in the opposite direction. While the first stator is connected to the engine, the common driven shaft of the both hydrostatic motors is connected to the external load on the output of the system.