English to Polish Tech/Engineering Construction / Civil Engineering

Normally what you would do, is you would put a rawl plug in there, but because
we're gonna have that shelf and we're gonna have some books on top of it, it's
gonna be really, really heavy. So what we've got is a hook mortice fixin'. This part
goes backwards, and it opens up those bits, and that's what pushes against the
hole, that actually gives you that tightness so it won't be pulled down.

Na filmie widać metalowe ustrojstwo podobne do kołka rozporowego, tylko że metalowe i w środku z haczykiem.