Anodized aluminum extrusions, 20mm x 20mm with 6mm t slots on all 4 sides
500mm TAZ 1-5 horizontal and vertical Lulzbot HD-EX0010 Misumi HFSB5-2020, TAZ 6 vertical
510mm TAZ 6 horizontal
Note that production TAZ 6 extrusions are a new spec with rounded corners and locking T slots. “Blemished” extrusions are the older style used in TAZ 1-5.
These extrusions are “manufacturer seconds” and may have modest scratches.