Product review (4 stars): Observations about Blackshark wireless weather station.
Purchased as a replacement for an old Acu-Rite weather station, this unit provides a "calibration" feature that allows for coordinating the read-outs of temperature, humidity, and barometric pressure to a known external source, such as Weather Underground.  As with many of these devices, there is no exact sensing of temperature and humidity levels; I have three different temperature reading devices, and each varies from another by some few degrees.  The function of calibration with a professional source does help to bring the unit's sensor readings into a reasonable proximity of accuracy.  One quibble:  the easel stand would be better replaced by a base that would allow the unit to stand straight upright, allowing for a more clear view of the digital read-outs.  Lastly, it takes a few days for the unit to provide a useful prediction of weather trends, as it has to "learn" weather changes due to changes in barometric pressure, as indicated by the pair of icons near the bottom of the display screen.  All things considered, this unit appears to be a better choice among several brands and models available.  Time will tell, regarding this unit's lifespan and functionality.