this is a very interesting watch for aviators or hickers. The baro and alt have to be reset once in a while but by in large very useful. The watch is large but very light and easy to adjust. the band has a double lock latch. The time is atomic so is very accurate. The temp is worthless while you are wearing it since it is taking body temp influenced by outside temp. The other features are useful but the only other one I really use is the timer.