The Sportline Cardio Connect is one powerful heart rate monitor that works in two ways. As a traditional HR watch and strap, it captures all the valuable, ECG accurate data you can use to monitor and maximize your workout. And when linked with your smart phone, the Cardio Connect creates a more robust experience, transmitting your heart rate feedback to your phone and to your watch at the same time. On your smart phone, the Cardio Connect links to Runtastic, a leading fitness app. This powerful combination of app and watch provides HR monitoring, GPS mapping, speed and distance tracking, and so much more. You can even save and share your training sessions on your smart phone and online. Cardio Connect truly is your wireless link to the wireless world.