For smaller applications the DUO Build System also comes in a 15mm x 15mm square extrusion. The 15mm profile of the 15mm Extrusion has slots on on all four sides that accept standard M3 hardware. Rather than using a T-nut, which is more expensive, slide a M3 hex head screw along the slot and adjust brackets and other build materials as needed.

This product is a 2-pack of 225mm pieces of extrusion, for when you need a shorter piece of extrusion without extra cutting.