Our top selling bypass shim material works for you where others won't. Light metal shims kink and twist. Brittle plastic tears and creases. Not a Peterson Shim! Our six-inch square of plastic impregnated fabric defeats the tightest jamb and most stubborn latch. And, does it time and time, again. The superior flexibility of our material provides a long lasting, strong and more flexible solution to your latch bypass problems.