This music addition of the Garmin Forerunner 645 has the great ability the hold up to 500 songs on the device, so you can now connect your favourite Bluetooth headphones, without having to connect to your phone to listen to your tunes. The watch features Garmin Pay, ready to make quick payments for when you don\\\'t want to carry cash or cards whilst out for a run - just pay and run. Useful training data, such as ground contact time balance, stride length, vertical ratio and much more, are available to improve your performance to the best it can be, these functions are available with a heart rate strap or the compact running dynamics pod. The watch is designed to give you wrist-based heart rate recording to help you analysis your fitness overtime. For analysing your performance after the 645 features a new monitoring tool called Training status, the can automatically evaluate your recent exercise history and performance indicators to tell you if your training productively, peaking or overreaching. The new anaerobic training effect metric opens a new insight to a critical dimension of training, telling you how your training is improving your ability to push the limits. You can even view your overall training load, which measures your exercise volume from the last 7 days and compares it to the optimal range for your fitness and recent training history. Still keeping you connected, the device allows you to receive and respond to text messages, find your phone, share live tracking with friends and family, and sync all your activities with Garmin Connect… and much much more. Overall the device allows you to train and feedback the best training method for you, whatever your sport. Key Features Battery life - up to 7 days in smartwatch mode; 5 hours in GPS mode. Heart Rate - Uses wrist-based heart rate3 to offer performance monitoring features, including evaluating your current training status. Running Dynamics - Provides advanced running dynamics2 including ground contact time balance, stride length, vertical ratio and more. Garmin Pay - Includes the Garmin Pay™ Ready contactless payment method1 that lets you make convenient payments with your watch, so you can leave your cash and cards at home. Download - Easily download up to 500 songs to your watch, and connect with Bluetooth® headphones (sold separately) for phone-free listening. Please be aware that this item is not available on Cycle to Work Schemes. Technology Buying Guide