A Review of Final candidates, post your favourite and win a credit by Nate Hamilton

I think I remember seeing an earlier version of this concept that I liked better. Overall I like the keyhole in the o. However there are some things that I just don't think are working on this logo:

1. Colors: The colors that you chose look more like a construction company then security company.
2. The stroke. The stroke is too thick and doesn't match the stroke on the key hole.
3. I might think about centering systems and making it all caps.

Out of the 3 the last concept is your strongest. I don't think you are done here, keep working on it!