Demonstrator and back shroud thereof

The utility model discloses a demonstrator and back shroud thereof, including the apron main part, wherein, should lap and have the arm that is used for supporting the arm in the main part and hold in the palm and be used for supporting the hand and the hand rest that can be held by the palm is provided with on and controls the platform to when the hand rest is held to the palm, the platform contact is pointed and controlled. During the use, the operator places the arm on the arm holds in the palm, and the hand is placed and the hand rest is held to the palm on the hand rest, at this moment, points and control the platform contact, and the operator just can control and control the platform promptly. In order to support alone arm and hand, prevent that the atress is concentrated through setting up arm support and hand rest in this application to control the platform setting and on the hand rest position, when the hand rest is held to the palm, point and control the platform contact. The aforesaid sets up the m