Shenzhen Cordier Electronics, the company behind SHYEEH, builds straightforward safety devices without the smart-home complexity. The CDR-803 combines a photoelectric smoke sensor with an electrochemical CO detector in a single battery-powered unit. That means one installation point handles two distinct threats: fast-burning fires and the invisible buildup of carbon monoxide from faulty furnaces or gas appliances.

The photoelectric sensor responds to smoldering fires with less false alarming from cooking or steam. The electrochemical CO sensor tracks the gas that binds to your blood and causes headaches before unconsciousness. The alarm triggers at specific thresholds, monitoring coverage between 215 and 323 square feet depending on room layout and ceiling height. This works best in bedrooms, hallways, or near sleeping areas where early warning matters most.

You supply the batteries—they are not included. That is a minor inconvenience for a device that sits on your ceiling for years. The plastic housing feels standard for the price point. No Wi-Fi, no app, no phone alerts. If you want a simple, code-compliant detector that does not require a subscription or smartphone setup, this SHYEEH does the job without fuss.