The TBT5-AI offers one internal four lane PCIe 4.0 expansion slot.  

The TBT5-AI offers the following ports on the rear exterior of the unit:

One downstream Thunderbolt 5 port
One downstream 10Gbps USB-C port
Three downstream 10Gbps USB-A ports
One 2.5Gbps Ethernet network port

*** NOTE - 2.5Gbps Ethernet receive/download throughput is commonly observed in the ~1.5–1.8Gbps range. ***