Review on Kidde Hardwired Smoke & Carbon Monoxide Detector with Battery Backup & Voice Alert - Interconnect Combination Alarm by John Duffield

AVOID! at all costs. Revane knows it is a defective product and is still selling it. Connected exactly as recommended and put in "new" batteries, and not sent, which sat on the shelf for 2 years. Within 4 hours of installation it started false alarms at 2am in the middle of the night, startling everyone in our family. Also, because of this, all the alarms in the house worked. This was a huge problem since I have high ceilings so I had to go into the garage at 2am and take a 14 foot ladder and rip the damn thing off the ceiling while still firing loudly. If you want that kind of experience, buy it. Don't say you weren't warned.