. . . "In a more preferred embodiment of a protective insert 10 according to the present invention, the insert 10 may be formed of materials selected from the group of natural or synthetic rubbers, elastomers, polyisoprenes, polyurethanes, vinyl plastisols, acrylic polyesters, polyvinylpyrrolidone-polyurethane interpolymers, butadiene rubbers, styrene-butadiene rubbers, rubber lattices, and other polymer" . .