CO detector CM L 4050 - adequate protection against toxic carbon monoxide (CO) The CO detector CM L 4050 with modern electrochemical sensor protects against toxic carbon monoxide (CO) with a penetrating alarm signal (85 dB). An LED display is integrated. A signal tone indicates the end of the service life. When the battery is low, it gives both a visual and an acoustic signal. Carbon monoxide detectors should not be missing in any household with a wood-burning stove or garage. Also recommended for camping. Including 3 x 1.5 V AA batteries. - 3 x 1.5 V AA batteries