This is a close-up view of two brass risers attached to the inside of the case. Look for holes in the motherboard and matching holes in the case. Cases vary, some come with plastic 'standoffs', most (I'm told) now come with brass risers. The risers must be put into the case holes, and then the motherboard later screws into these. Some boards require small washers with the screws, some dont. The general advice seems to be use all risers available, including at least one near the centre of the board. We'll leave the case for now and go prepare the motherboard.