Are designed for use in place of standard and thin height hex nuts in applications where, for reasons for safety or appearance, it is desirable to cover exposed bolt ends. They are also suitable for sealing internal or external pressures, up to 80 psi past the bolt threads, provided a proper seal is effected between the nut seat and its mating surface. Maintain locking effectiveness up to 250 Degree F. The locking insert and cap are an integral part. Stock black.