First Alert CO400 Battery Carbon Monoxide Alarm vs First Alert SMCO100 / SMCO200V Combo
Side-by-side specs from each maker.
Only the differences are shown.
| First Alert CO400 Battery Carbon Monoxide Alarm | First Alert SMCO100 / SMCO200V Combo | |
|---|---|---|
| Type | Smoke or CO alarm | Smoke or CO alarm |
| Alarm | CO | combo |
| Sensor | electrochemical | Photoelectric (smoke) and electrochemica |
| Power | Battery operated | AA (2 alkaline, replaceable) |
| Interconnect | none | Not listed |
| Standards (maker) | Listed to UL 2034 Standard | Not listed |
| Replace after | Not listed | 10 years |
First Alert CO400 Battery Carbon Monoxide Alarm
A battery-operated carbon monoxide alarm with an electrochemical sensor, a single test and silence button and an 85 decibel horn.
- Portable
- Single test and silence button
- 85 decibel alarm
- Battery powered only
First Alert SMCO100 / SMCO200V Combo
A battery-powered smoke and CO combo alarm that runs on two replaceable AA batteries. The maker says the unit itself should be replaced at least every 10 years.
- Replaceable AA batteries
- The maker lists a replacement interval of at least every 10 years