The rollers clearly have wire grooves (there is even a close up shot of them), but there is no mention of the wire diameter that it can be safely used on, or even that it can roll wire at all.
What is the maximum wire diameter for this machine?
Yes, the rollers are detachable for cleaning according to the product description. The upper roller can be easily removed, simplifying the retrieval of processed workpieces.
The product description states it can handle materials up to 20 gauge thickness, which is 0.035 inches thick. Trying thicker materials than specified may damage the machine.
Based on the product information, it has a maximum capacity of 20 gauge, which is relatively thin. It may not handle much thicker materials than 20 gauge sheet metal.