Series III, Used in systems which require a small hydraulic displacement. Rugged construction. Designed with premium quality longlife components. Units available for use with either DOT3/DOT4 brake fluid. Used in systems which require a small hydraulic displacement. Rugged construction. Designed with premium quality longlife components. Units available for use with either DOT3/DOT4 brake fluid.:Haldex Pressure Converters are designed as brake actuation devices and are not to be used for parking or holding brake applications.