Smoke and Carbon Monoxide Alarm

I show a new style smoke and CO alarm.

Easy to install smoke detector

Here is an easy to install smoke detector. I like the style and features.

10 Year Tamper Proof Smoke Detector

Visit http://www.askthehardwareguy.com for more tips.
If you are installing a new smoke detector, I would look at the 10 year smoke detector. It has a battery that is designed to last the life of the alarm.
Regular smoke detectors need to have the battery replaced every year and the whole unit needs to be replaced every 10 years.
Some 10 year smoke alarms have sealed batteries that cannot be removed. They are an excellent choice for landlords. They also have units that have locking mounting brackets to keep them in place.