Only with the correct fastening the window security device will find a long-term hold in the wall and withstand attempts to break it open.
The DIN standard 18104-1 states:
"[...] In case of poor fastening possibilities (soft or hollow or foamed substrate and plastic windows with and without metal insert and wooden windows) and/or good attack possibilities from the outside, more fuses and additional fasteners (compound mortar or through bolts or fastening anchors) should be used. At least one fuse per door or window should be lockable. If the frames themselves are too weak to make a useful retrofit, it may make sense to reinforce the frame, for example. [...]"
With most products we supply fastening material. In exceptional cases, it may be necessary for you or the installer to lend a hand once again. It is important that our products are fastened in such a way that they can correctly fulfill their task as burglary protection.