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A screw with dual devices that can be loosened after a worn-out.
It wasn’t easy to unscrew the previous flat-head screw using a different tool when it was worn out because there was no place to hold.
If the screw is worn down by a screwdriver, it can be loosened using a hex wrench or a spanner through the hexagonal intaglio or emboss.
Sasang-gu, South Korea