8020, 1010, 10 Series 1 Inch x 1 Inch T-Slotted Aluminum Extrusion DIY Extruded Linear Slot Bar Rail 80/20 (12" Long, Black Anodize): Amazon.com: Industrial & Scientific
Slotted Aluminum Extrusion - 20mm x 20mm - 610mm long : ID 1221 : $7.50 : Adafruit Industries, Unique & fun DIY electronics and kits
40mm x 40mm Lite T-Slotted Aluminum Framing Extrusion - Alufab Inc.
Amazon.com: 8020, 3030, 15 Series 3" x 3" Aluminum T-Slot Extrusion x 18" Long T Slotted Extruded 80/20 Profile : Industrial & Scientific
1.5" x 1.5" Lite Smooth T-Slotted Aluminum Extrusion – Faz-Store
Aluminum Extrusion (20mm x 20mm) - Clear – Inventables, Inc.
E40-4084L-C- 40mm x 80mm 4-SLOT ALUMINUM EXTRUSION (Cut To Length)
50mm x 50mm T-Slotted Aluminum Framing Extrusion - Alufab Inc.
8020, 3075, 15 Series 3" x 0.75" Aluminum Smooth T-Slot Extrusion x 36" Long T Slotted Extruded 80/20 Profile - Shelving Hardware - Amazon.com