Even when you measure three times, The bridge just isn't straight. You can be one hair off and need to fill the holes and start over again. I ordered a bridge with six screw holes so installation will be a breeze. This bridge forces you to mark a spot, remove the bridge, and then guess where to drill. I drilled in the exact spot I marked and it was wrong. I'm not sure how far in the bridge needs to overlap the screw, But i'm on my fourth attempt and so far haven't been able to do it. This has been a living nightmare and I have ruined my body in the process.