Review on 🔋 White First Alert CO615 Dual-Power Plug-In CO Detector with Battery Backup and Digital Display by Josh Allen

Note that the blue display backlight does not stay on (despite the misinformation on the First Alert site). As a result, the LCD display can be "read at a glance” just a few seconds after a button is pressed. For this reason, I prefer Kidde CO alarms with an LED display that I can easily read from across the room and out the window. Darkness anytime without pressing a button. Note that a quick press of the button does nothing but blink the green LED; The button must be pressed for a second or two to display the maximum value, or turn on the backlight for a short time, or start a self-test. Expires in 7 years but no explicit date code is printed on the device. So I had to add my own marker date code. The batteries were made over a year ago so they were probably a year old when you received them. (competitor products last up to 10 years) Downgrading due to misleading product description by First Alert making me regret the purchase.