Disclosed are systems, methods, and non-transitory computer-readable storage media for conducting sales. The illumination system includes a tail lamp assembly, a sensor and a controller for controlling the operation of the tail lamp assembly. A gate area of a second transistor is also arranged symmetrically on portions of the first and second active areas. When hydraulic oil serving as the fluid is supplied to pressure chambers, a pair of piston rods are extended, and linear actuator force is transmitted to the connecting portions of the mounting portions, thereby transmitting bending force to the joint of the user.