Instructions seemed overwhelming but were very easy to follow. The setup is very logical and most people will prob. figure it out without the use of the manual. Calibration was easy. Compared to other devices (therm., compass, etc.) and found to be quite accurate. Not on-the-dot but only off by 2-3 degrees (both in temp. and compass reading). Have dropped it, kicked it, and smashed it - and it's still going. Would recommend, esp. for the price.