Pacbrake announces the PRXB Exhaust Brake specifically designed and manufactured by Pacbrake, approved by Hino Motors. The new PRXB exhaust brake is offered for North American 4 and 6 cylinder Hino conventional trucks. Pacbrake's premium performance exhaust brake is engineered to maximize braking power by creating constant backpressure as engine speeds change, maintaining optimum retarding performance through the entire RPM range.