This is an expandable cantilever brush storage box, although you can remove the brush dividers to make it into a more generic storage box.

To assemble the 4 tier version shown in the image (base, 2 middle drawers, top drawer, handles) you will need:

• 1 Base (Deep or Shallow)
• 4 Middle Drawers (2 mirrored)
• 2 Top Drawers (1 mirrored)
• 4 Short Arms
• 12 Long Arms
• 2 Handles (1 mirrored)
• 88 m3x8mm bolts
• 88 m3 heatset inserts (max 6mm length)
• 88 m3 spring washers
• 176 m3 flat washers

To assemble, set the inserts into the drawers, then bolt the arms on ensuring that there is a washer either size of the arm and a spring washer between the box and the inside flat washer.

I used some thread locker to ensure the right tension and avoid the bolts loosening over time.