NEW DSC WS4913 Carbon Monoxide Detector / Factory Sealed Box. These detectors were manufactured in March, 3rd 2018 The expiration date on the detector says March, 2023 Though it might sound odd, it’s true that carbon monoxide detectors expire. Carbon monoxide detectors expire because the sensor part that reacts with carbon monoxide gas loses sensitivity as time goes by. The average carbon monoxide detector can last somewhere from five to ten years. Most carbon monoxide detectors will have an expiration date on the back to let you know when you should replace them. It can also be helpful to write the date you bought your carbon monoxide detector on the device itself as a useful point of reference. Here are some things you can do to get the most out of your carbon monoxide detector during its lifespan: Test and clean your carbon monoxide detector monthly If battery-powered, replace batteries twice a year Place it in an area out of direct sunlight that’s free from excess humidity, smoke, and dust Replace the detector if it has excess dirt and grime that can’t be cleaned, if it begins chirping or giving false alarms, or if it’s otherwise faulty. ALL Carbon Monoxide detectors, regardless of make, model or company. Is to be replaced 5-6 years AFTER installation of a new device to insure proper Carbon Monoxide readings! These units will need to be replaced in the year 2028 if installed in 2023 Item is NEW *Box Opened For Picture* Item comes exactly as pictured. If it is not in the picture, it does not come with the item unless stated in the description. You may not receive the exact unit pictured, but one in similar condition. Check compatibility with your system. We are not responsible for incompatibility or improper installation. 20% RESTOCKING FEES AND SHIPPING WILL BE CHARGED. IF ITEM IS FUNTIONAL OR INCOMPLETE. Your feedback is extremely important to us! If you are satisfied with our service please take the time to give us positive feedback. We tremendously appreciate it! We strive for your complete satisfaction. Likewise, if you have any issues, please contact us first, and we promise we will do our best to satisfy your needs and solve the problem. If we resolve your problem, we kindly ask you to still leave us positive feedback. Your kindness will be extremely appreciated!