Combination Return / Suction filters are designed to filter an open loop return circuit and provide suction line boost to the closed loop charge pump in hydrostatic transmission applications. Utilizing the 0.5 bar back pressure valve ensures positive pressure to the charge pump inlet minimizing the potential for cavitation, especially during cold start conditions. Many options are available including suction line safety screen and the possiblity to mount on the side or bottom of the tank with anti-drain protection when servicing the filter element.