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
Extruded Aluminum T Channel Manufacturer & Supplier
Aluminum Extrusion Slim T-Nut for 20x20 - M4 Thread - pack of 50 : ID 1157 : $11.95 : Adafruit Industries, Unique & fun DIY electronics and kits
T-Plate for 2020 Aluminum Extrusion : ID 1219 : $2.95 : Adafruit Industries, Unique & fun DIY electronics and kits
E45-4545-C - 45mm x 45mm ALUMINUM T-SLOT EXTRUSION(Cut To Length)