Carbon monoxide alarm, Premier White®. Biotechnology-based, infrared gas sensor mimics human response to carbon monoxide. Detects low levels of carbon monoxide (70 parts per million). Maintenance-free. Solid state sensor never needs replacing. One-year warranty. Detects toxic CO gas resulting from incomplete combustion emitted from appliances, furnaces, fireplaces and auto exhaust. Quick recovery; rapidly returns to original state when carbon monoxide is eliminated from environment. Every unit is 100% gas-tested to ensure accurate, timely response. Microprocessor intelligence; self-tests every 10 minutes. Supervises sensor and alarm circuit status to ensure protection. Easy to install. No wiring, battery operation allows unit to be located almost anywhere. Energy-efficient design extends battery life to more than one year under normal use. Low battery warning, chirps, and LED double flashes. Test/retest button.