Carbon monoxide detector adopts advanced electrochemical sensor, which can accurately detect carbon monoxide level and respond quickly, saving your life at the first time in case of fire When the alarm detects that the CO concentration exceeds, the red LED number will also flash and sound 70dB Powered by 2 x 1.5V AAA battery powered carbon monoxide detector (not included), low current consumption, super long standby time. Simple to use, only one test/reset button, with mounting accessories, just drill holes in the correct position, and you are done The carbon monoxide detector is easy to carry and set up. It comes with a simple test/reset button and simply unscrews the back cover of the detector and it is screwed to the wall or ceiling in the correct position. Color: White Material: ABS Package Contents: 1 x Detector 1 x English manual 2 x Screw 2 x Anchor plug 2 x Double-sided tape Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.