A multistage oil seal includes a plurality of lips in a plurality of stages disposed around a motor shaft of a machine tool along the axis of the motor shaft to protect internal members of the motor from the cutting fluid. The administering includes randomly selecting a set of related images from a database of images, randomly selecting one image that is unrelated to the set of related images, displaying the set of related images along with the image that is unrelated to the set of related images, and prompting a user to identify the image that is unrelated to the set of related images. The UUID can then be used to track services and correlate service information between multiple systems. The cap can be lifted up to protrude or be retracted in the body of the mouse via an external force, the lifting up and the retraction of the cap cause the shape of the hand gripping the mouse to change, preventing fatigue in the hand.