All-day power. Enjoy up to 13.5 hours of battery – 4.5 hours in earbuds and additional 9 hours in charging case. All-day comfort and a secure fit. Customizable fitting options - wear one or two earbuds.Advanced heart rate monitor. In-ear precision for optimized workouts and fitness analysis. Automatic rep counter and race pace predictor.Guaranteed durability. IP67-rated waterproof design.