Hi,

the description mentions the tools to be designed for Acrylic and PVC - so high chance for HSS which wouldn't even be a bad choice for this kind of application.
HSS can be ground significantly sharper and is much more ductile than carbide - the first being interesting for acrylic and the latter in case your tools tend to break before getting dull.

But if you really want to know you need to ask the seller for clarification or just buy and see what you get.

Christian