Stainless Steel Lifting Expansion Eyebolt with Ring Expansion Pack of 5

Principle of operation: Place the expansion bottle in the ground 
or in the wall outlet, and then tighten the screws on the screw 
with the key. The bolt comes out as long as the metal shell does 
not move. In this way, a larger screw head will extend to the 
metal shell, which will fill the entire hole. Now, the expansion 
screw can not be pulled.
Widely used in fences, doors and windows, canopy, fixing air 
conditioners, home decoration, engineering, and more.

The expansion is created by tightening a screw with a thread
 that pulls the tapered cone that widens the sleeve from the hole
 walls.