I had the barometer / altimeter a week on tour in the Alps this (I tested it up to 3300 meters of altitude, the scale ranges up to 5000). It works flawlessly and achieved with closer inspection even a slightly better resolution than the height specified 20m. The pressure measurement seems to be stable and not distort even at different temperatures. The build quality is reasonably solid. The included strap and carabiner are practical. I had the barometer secured all the time in your pocket and a carabiner to a belt loop of his pants, so it could not be lost even when climbing. The height is calibrated at a point of known height simply by turning the scale. The holding tight enough so that they Hiking / climbing with the device in your pocket does not slip even after a whole day. The device is entirely mechanical and does not require a battery - it can not, of course, save as other digital devices, maximum and minimum values or integrate vertical meters. The included Compass is a nice addition. It works, but is of course much too small in order to aim for right. The thermometer is also quite nice, but also quite small and not overly accurate. However, it will do just fine if you want to know roughly the temperature.
Conclusion: I think the device is full for the price ok. Anyway, I'm fully zufreiden and will take it on all other mountain walks.