It is a rayon fabric with a silicone rubber coating and is PSA backed. In our tests we found it had superior non-slip properties and was highly resistant to glues.
Especially useful if applied to a router plate to ensure the router is firmly clamped to a table and doesn't move during operation. Can also be used on magnetic shop accessories (dust chutes, fences, shop lamp, etc.) to keep themfrom slipping and to prevent surface marring.
Sold as a 1" x 12" strip.