Absolute top assist in accurate alignment of switches and sockets. The spirit level is placed on top by means of magnetic and straight attack on the switch / socket. Now you need the whole only align, screw tight - and you're done.
Time and especially "nervous" -Ersparnis is very high. Especially when implemented by combinations.
Conclusion: It is power in the tool bag of every electrician domestic installations, as well as a recommendation for any home improvement of several would align its sockets / switches (home renovations).
