Bulldog Alarm Systems!?!?
Kidde and First Alert (i think) both make interconnected smoke detectors that are wired and wireless. If any one of the interconnected detectors activates, the other detectors will sound the alarm. Hope that helps and be safe!
skull crushers definitely..you can either use a curl bar or a free weight..i like to lay on my back on a bench and use a free weight..just make sure to keep your elbows in while doing them and bend only at your elbows to get the most effective workout.