So do they have the description wrong on the Chevy/GM Accessories website wrong then??
https://accessories.chevrolet.com/product/standard-bed-embark-ls-retractable-tonneau-cover-by-advantage-associated-accessories-19419843?vin=3GCUYGET3LG363107&categoryId=98027
I see Polycarbonate Construction but nothing indicating Aluminum in the description. From the link above:
MSRP $1,929.00*
Unique Trax Rail design allows for rack and accessory compatibility that offers enhanced hauling options (Thule Cross rails sold separately)
The rigid polycarbonate construction helps provide impact resistance and UV protection, and will hold up to 500 lbs. evenly distributed — easily supporting heavy loads
Sealed Ball Bearing Design which allows the cover to roll maintenance free without binding, and be key lockable in any position
Patented Flush Front Cover for a low profile appearance and minimizing water intrusion
Exposed stake pockets
UV treated to help with protection from sun
Kit includes, Tonneau cover, hardware and keys