[aidenn0]

You can get Class I by preventing human access, I'm guessing the Pro can't have the same interlocks for some design reason.

[mlmilleratmit]

I think the pro is 'feed-able', wonder if that's it.

[aidenn0]

Yeah, I just saw that on their youtube video; the sides can remain open during operation to allow etching/cutting of materials larger than the enclosure. That means human access is possible, so therefore the class IV.