The Carlisle Brake & Friction single circuit and parallel circuit, modulating hydraulic control valves provide modulating output pressures in a range of 600-3,500 psi (41 to 241 bar). The output pressure for each pedal may be independently set to enable complete control of the vehicle brake system. Treadle pedal force ranges from 45 to 68 pounds (200-300 newton) for the dual valve, depending upon output pressure. The treadle pedal force for the single valve ranges from 17 to 56 pounds (75-250 newton), depending upon output pressure. The Carlisle 2102 Series in-line retarder/ brake control valve provides electric retarder control with sensor output, plus hydraulic brake modulating control in one component for easy installation and reduced system cost. Retarder control is achieved using a contactless rotary sensor. The sensor provides a dual redundant output signal, either 5 or 10 VDC, for the retarder control.