metal molly fastener fixed in pre-drilled hole in sheet of moisture-resistant drywall, the view in the section of end of sheet

anchor assembly background bolt can collet condition connection construction diameter dowel drilling dropdown drywall end fastener fiber fix fixed fixing gypsum hang head hole hollow incision insert install installation iron isolated length long metal moistureresistant molly mounting object open predrilled reliable screw screwing section see shape sheet shiny spacer steel strong tool twist view white