This series of power-off brake must operate oil-free to avoid affecting torque; it can be horizontally installed, and vertical installation is allowed in certain low-speed applications. The square core (spline sleeve) must be axially fixed on the shaft. When the brake is de-energized, the spring pushes the armature and friction plate, clamping the friction plate between the plates and the armature to achieve braking. During installation, ensure that the friction plate can slide freely on the square core (spline sleeve), and maintain the perpendicularity between the shaft and the installation base, allowing the friction plate to rotate freely between the armature and the plates when the brake is energized, with no noticeable noise or damping.