Wesaf Smoke Detector Tester is a convenient and safe solution for testing the functionality of commercial and residential smoke detectors. Smoke detector tester sprays are a convenient way to ensure your smoke detectors are functioning properly. Smoke detector tester sprays simulate the presence of smoke, allowing you to test the functionality of your smoke detectors without creating an actual fire hazard. These sprays are typically aerosol-based and are formulated to mimic the particles found in smoke. Hold the can 60-120 cm below the smoke detector and spray at the unit for 2-3 seconds. Wait for a few seconds for the alarm to sound off. If the alarm does not sound within 5 seconds, immediately repeat the process. Some units have built-in delays to reduce false alarms. If the alarm still fails to sound, check the unit for malfunction or flat batteries.