I want to know the answer to the following question:
Several manufacturers offer what?
All the background I'm provided with is that "These offer performance comparable to internal drives, limited by the current number and types of attached USB devices, and by the upper limit of the USB interface (in practice about 30 MB/s for USB 2.0 and potentially 400 MB/s or more for USB 3.0).". Is that enough to answer the question?
Answer: no