Kidde uses advanced Nighthawk electrochemical sensing technology in its CO alarms. With this technology, the presence of carbon monoxide causes a chemical reaction that instigates a current flow through the circuit. Alarms with electrochemical sensors are more stable during humidity and temperature changes and resist reacting to common household chemicals that may cause false readings. These models are conveniently sized and provide the highest level of accuracy available. Low power requirements (standard alkaline batteries) also mean that advanced features such as digital display and Peak Level Memory are possible with Kidde products.