New here, went in to the dealer last night to look at a CPO 2017 Sierra Denali but instead drove home in a 2020 6.2 Denali CarbonPro.
I ordered through the dealers parts department - went with the soft version. The dealer is installing it for an additional $50.00. Ordered this morning, they said it will arrive tomorrow or the day after. I would love to have the locking feature, but to me it's not worth the extra $500.00 (they're over priced as it is).
Did some research and read through this post, here's the link, price, and part numbers:
Soft Tri-Fold Tonneau Cover (Not Lockable)
Part No: 84791288
Price: $600.00
https://accessories.gmc.com/product/short-bed-soft-tri-fold-tonneau-cover-with-gmc-logo-(for-models-with-carbonpro-bed)-84791288?year=2020&make=GMC&model=Sierra 1500&categoryId=98027
Hard Tri-Fold Tonneau Cover (Lockable)
Part No: 84791287
Price: $1,100.00
https://accessories.gmc.com/product/short-bed-hard-tri-fold-tonneau-cover-(for-models-with-carbonpro-bed)-84791287?year=2020&make=GMC&model=Sierra 1500&categoryId=98027