Environmental conditions, including temperature, altitude, and barometric pressure, are gathered from your phone’s location services and automatically transferred to the rangefinder. That means you need cell service to get live updates, a serious limitation of the system. But you can manually input these factors, along with wind speed and direction, and adjust them as conditions change or when you're out of cell range. For shooters with basic operating knowledge of a smartphone, the system is simple and fairly intuitive, and it really shines with a partner, one of you ranging and the other on the gun. Single-user utility is slower, simply because it takes time to range, then get back in the scope, place the hold0ver dot, and make the shot.