Drawing from Soundcore's Anker heritage, Arc is engineered with a premium Arc's water-resistant shell and an interior Nano-coating offer outstanding defense against liquids such as water, rain, and sweat. Li-ion battery and exclusive power management technology. Noise reduction technology blocks out distracting ambient noises.The adjustable metal ear hooks hug the shape of your ears, while the silicon covering provides grip to ensure Arc stays in place-even during hardcore workouts.