The computer has 2.8GHz Quad Core i7, 16GB DDR3 memory, Intel Iris Pro 1536 graphics, and 1TB SSD.

I've done a fresh install of Big Sur.

Computer works fine. It was used primarily as a stationary desktop unit, so it has only a few light scratches on the bottom of the case, no problems with the screen. Sold as is, though guaranteed to work on arrival.