5 lbs, but, because of its flush mount aspect it does give some aesthetic value to the room. The main attraction is the speaker, which is located on the small middle section which will work in most cases along with the LED ring for example, when using Alexa, the LED will be solid blue when Alexa is processing your request and will become half red when the microphone is muted. I can’t really say that the speaker is among the best, but the fact that you position the device on the ceiling definitely makes it sound better than the regular Alexa devices. The Onelink Safe and Sound is a wired smoke and CO detector a battery only variant for has not yet been released, so, it is advisable that the installation should be conducted by a professional. If you decide to go at it by yourself, these are the steps you need to take: first, you need to make sure not to mount the device in locations where the temperature is either below 40ºF or above 100ºF and the humidity is within the 20 to 80 % range non condensing; secondly, try to avoid spaces where the air is not circulating properly such as in the corners of the room – you can mount in on the wall or on the ceiling and also keep at least 20 feet from any cooking appliance the main source of false alarms. The most common types of smoke detectors are those that are equipped with either a ionization sensor or with a photoelectric sensor or, of course, both. The first type of sensor is very sensitive to smaller particles, so, they’re very good at detecting fast burning flames, but, unfortunately, are also prone at giving false positives for example, while cooking. The second type of sensors relies on detecting larger particles specific to slow burning, smouldering fires – such as a cigarette left on the sofa by using a light source inside a chamber which points away from the sensor, but will deviate its course towards it at the moment smoke enters this chamber. The First Alert Onelink Safe and Sound uses a photoelectric sensor for detecting smouldering fires and an electrochemical sensor for detecting CO emissions so it uses minimal power to accurately detect any change in the concentration of CO from the atmosphere. In case the sensors detect rising levels of smoke or CO, the LED light will flash a red colour and you’ll hear a voice telling you the location of the detector in case you have more than one devices inter connected. The alerts can be silenced by pushing the Test/Silence button for a minimum of 3 5 seconds or using the app, but be aware that this is only temporary and you will need to identify and fix the problem until the alarm will sound again you get 15 minutes in case the sensor detects smoke and 4 minutes when the sensor detects high levels of CO.