Thruster brakes 300-18 are fail-safe brakes that employ an electrohydraulic thruster to keep the brake open. The thruster piston rod expands and the brake is removed when power is applied. The piston rod retracts and the spring engages the brake when the thruster is switched off or power is lost.Thruster brakes 300-18 are very easy to install as well as simple to use. We keep common thruster models in stock, repair thrusters, and offer engineering and technical support. They are very economical to use.