In our old apartment I bought for windows and balcony doors lockable handles, which cost about twice as much. Unfortunately, you could not tilt in the locked state the window still open. This means that you have the key somewhere handy. In very young children, the handles are secure, but more clever children - at least our know 4 where the keys were to find and has easy open.
Likewise, I've bought a couple of cabinet backups that I could have saved me Sohnemann had very early and quickly figure out how to operate this had particularly interesting design.
So I think you need, similar to security closures on bottles, a stiff hurdle, everything else uses the long run nothing.
INSTALLATION
You have to dismantle the handle and put the fuse under the handle.
The lugs our handle support, the quasi produce a lock with the window, are unfortunately a little larger than the wells of the fuse. this we have drilled. (Window of Fa. KOWA)
That is probably the only downside to this type of assurance that the handle must be to ensure accurate fit. And here appears to be no standard to insist on windows.
