Those are parts and system labels are innovative features of the Build By Numbers system. The part label has a number to make it easy for you to order a replacement if the part gets damaged. System labels indicate what component each part is used to make. System labels are also color-coded for exhibits that contain multiple components. Parts connect to similarly colored parts. For example; Blue parts are used with other blue parts, but are never used with red.
Although the Build By Number system does not require instructions, we include them. They are helpful to know what the display will/should look like when completed and also useful for replacement of graphics.