The OmniShield state-of-the-art smoke sensor is the most reliable smoke detection unit in the industry due to both the quality of its components and the precision manufacturing methods.  Smoke detectors in large commercial, industrial, and residential buildings are usually powered by a central fire alarm system, which is powered by the building power with a battery backup. Domestic smoke detectors range from individual battery-powered units, to several interlinked mains-powered units with battery backup; with these interlinked units, if any unit detects smoke, all trigger even if household power has gone out. Most fatal fires occur at night when people are asleep. Often, victims never wake up. A working smoke alarm will detect smoke and sound an alarm to alert you, giving you precious time to escape. A smoke alarm is an often overlooked, but very important part of keeping your home safe. Many fire deaths happen in the home, especially at night or early in the morning when people are asleep.