Note: do not put the nut unscrew it to prevent the bolts from falling into the hole when the drill is deep. After tightening the nut 2-3 buckle, it feels that the expansion bolts is relatively tight and not loose, then unscrew the nut, and align the fixing piece with holes on the fixed item to the bolts and install the gasket or spring installed on the outside Tighten the nut with the washer.
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