This is second barometer which I bought from this company an I will order third one because my friends when they see it I am forced to give it to them, they are amazed with look and accuracy of the product. About calibrating: Go to www.ventusky.com , chose your town, press air pressure and read it with mouse over the place. Original barometer is set for altitude of 400 meters, mine is 140 and difference is obvious. Then with a small flat screwdriver calibrate on readed value.
All OK beatiful barometer