Sean,
I don't know about these new items from Fine Molds but the sets I've used very from Cutting Edge I believe. They were made of some sort of flexible resin not vinyl. I don't think vinyl would do as it wouldn't hold it's shape after bending. The flexible resin belts will hold their shape after bending them. The best I can remember mine were quite easy to bend too, but I used my Wife's hairdryer to heat them a little mainly out of concern for breaking them.
Never built any of Fine Mold's Star Wars models but there aircraft kits aer quite nice as are their Japanese Miget Submarine kits.
Highest Regards,
Gregory Jouette