Guard-566 Portable Carbon Monoxide Detector, Rechargeable CO Detector with Back Clip, Vibration, Visual and Audible Alarms, 168h Long Standby, Adjustable Alarm Thresholds for Home, Work Use

Disclaimer to start with- I cannot review the accuracy of this unit as I have no way of testing that.With that aside, I was VERY impressed by this device. It comes in a nice plastic armor case- not Otterbox style tough so I wouldn’t drive over it with a car, but very usable to keep it protected. Custom foam cutout in the box keeps it nicely arranged. It fits perfectly in the hand, and the menu system is pretty intuitive. Screen is nicely backlit and easy to read. The menu offers several options so this would be good as either a momentary sensor or a ‘leave it in place for a while to get readings over time’ detector (the battery lasts several days and it can take readings over time), making it a most versatile device. I also appreciate the excellent manual that goes over all the functionality in great detail. That also includes some user re-calibration pages, and some (password locked) technician re-calibration screens that an authorized service center can use to do a more detailed calibration. This is the sort of thing I’d expect on a more expensive instrument, so it’s good to have something at a ‘disposable consumer product’ price that has that higher level of quality.With that all said, there were three things that didn’t quite make sense to me. One was the included mounting bracket. The device has a clamp on the back that’s not really a belt clip. The other thing in the box isn’t a bracket, rather, it appears to cover the sensor (perhaps to hook up a tube of some kind). By my read it wasn’t mentioned in the manual at all. Finally, the charging is MINI-USB- not micro-usb or usb-C. It includes a cable so this isn’t really a big deal, but it’s worth noting.Overall I’m quite happy with this device though.