"Good strong fixing. I used them to fasten radiator brackets to a hollow wall. The legs spread out behind the plasterboard to spread the load effectively. If installing with a screwdriver you may find that the outer sleeve tends to rotate in the plasterboard. I got round this by gripping the lip of the outer sleeve with a mole wrench until I felt the legs expanding, then you can let go of it and allow the fixing to settle in as you tighten it up."