What PCIe slots does the QNAP TS-873A have, and does it come with 10GbE?

The [QNAP TS](https://www.amazon.com/s?k=QNAP+TS&tag=wehavethat-20)-873A has PCIe Gen 3 x4 slots and ships with a 10GbE card pre-installed in one of them. You can use the remaining slot for more expansion or connect QNAP expansion units for additional drive bays.