Kidde Hardwired Smoke & Carbon Monoxide Detector, Battery Backup, Interconnectable, LED Warning Light Indicators, 4 Pack & Heat Detector, Hardwired with Battery Backup & 2 LEDs, Interconnectable

• Product 1: 2-in-1 Detection - Smoke & carbon monoxide detector combo alerts you to both smoke & fire events as well as poisonous, CO gas in a single device Product 1: 24/7 Self-testing components are always checking the device to ensure it's operating as expected (not a substitute for a manual push test) Product 1: Easy installation mounting bracket included for quick installation in 4 orientations Product 1: Photoelectric sensor detects visible fire particles associated with slow, smoldering fires, while the electrochemical sensor detects carbon monoxide Product 2: Heat detector alerts to temperatures rising above 135⁰ Fahrenheit & sounds an 85-decibel alarm to help protect your family Product 2: Protects during a power failure - heat alarm operates on a 120V wired power source with 9V battery backup Product 2: Quick-connect power harness makes installation fast and easy Product 2: Test Button lets you check that the heat sensor’s electronic circuitry, horn, and battery are working