Comfortable 3D Sleeping Eye Mask - Soft & Relaxing Sleep Aid - Black

Self-tapping thread inserts have strong resistance to vibration so as to prevent loosening. Thread repair allows to continue using the same specification of screws. Simpler, more convenient and faster than ordinary steel wire thread inserts. The thread inserts have self-tapping ability so that the base metal does not need to be tapped beforehand. Self-tapping thread inserts have a maintenance effect on damaged threads.