CRB Cork Jig Saw with 12 Blades

As expected!

Works great. Minimal material loss. Cuts are tedious, but this gets the job done Have not broken a blade yet, but will probably break one now that I’ve just written this.

Does the trick

Cuts cork and foam fine

Excellent feel in the hand. Micro blades don't take off too much material so the diameter of the rings barely change.