Window restrictors child locks?

advice_please_2

Looking at something like this for our upstairs windows, as having young kids want to give a bit more safety and so allows us to open the window

http://www.babysecurity.co.uk/products/3093/Jackloc-Window-Restrictor-Child-Lock-White.html

My concerns are
- how secure are they
- drilling/ screwing into PVC frames therefore marking them when we move on
- fittings, is it simple?

Dan-Dan

they are secure , but you need to think about what happens in the event of a fire ? , fittings , simple enough , when you leave , leave them installed!

phill99

I fitted these for a customer recently in a 3rd and 4th floor maisonette. Very easy to fit. 9 took about an hour and a half.

They are key lockable. Take the key out and put it in a place high up n the room where the children can't reach it but you can access it in the event of a fire.

Just leave them in situ if you move. Buyers may welcome them.

advice_please_2

Thanks

Any recommended ones?
I'm useless at DIY

I assume drill and screw in fittings? But do I need special drill bits and techniques to ensure I don't break pvc and behind it?