An endoscopic device for generating acoustic waves with a sheath defining a center axis contains a first transducer for generating a first beam of acoustic energy radiating outwards of the endoscope sheath and a second transducer for generating a second beam of acoustic energy radiating outwards of the endoscope sheath. The redundant memory cell array is arranged in a position apart from the main memory cell array and the write current source is commonly used by the main memory cell array and redundant memory cell array via the common node. The rear end of the sealing piston and the front end of the working piston are exposed to the pressure of the fluid in the second partial volume while a movable adjuster piston is provided to which compressed air can be applied and which is coupled to the endstop that determines the extent to which the valve opens between its closed and its open positions. When the policy is applicable, and the application is not classified as interacting with a user in the device user interface foreground, the Internet service access request is blocked. Various bonus presentations or attractive presentations may be displayed on a plurality of video screens. A first additional reflector for reflecting light from a light source to direct forward is arranged at a vicinity on a rear side of the movable reflecting portion.