I'm just getting started with 3D printing and was hoping you might shed some light on the purpose and operation of this component. Thanks [basketball stars](https://basketball-stars.co/)

At Instructables.com they now have "Classes" you can take that cost around $30. For the month of October 3 of these classes are free. One of which is for "3D Printing" (If you are new to 3d printing GO NOW a take the class before free trial is up). The class uses this tool to check how much space you have to allow between parts that fit together. It was to big for my printbed so I had to cut it to fit.

hello there I'm new to 3d printing so could you please explain what this item is used for and how do we use it Thanks