100 mm x 100 mm x 1 mm rectangle to test how level the bed is on your Snapmaker. Default size leaves space for bed adhesion options such as a skirt or brim.

This will help you see where on your beed you need to adjust the leveling. A good print on a level bed will look even all around the square. A bad print from a bed that isn't level will be uneven in places or not even adhere to the bed.

Use the scale settings in Cura or your slicer of choice to adjust the model to your taste.