True Wireless drives your performance with superior sound, Adaptable Acoustics that lets you tailor the sound for the level of focus or awareness you prefer and an outstanding secure fit. Signature sound. Powered by Sennheiser TrueResponse transducer, a 7mm dynamic audio driver that delivers a high-end sound experience with full bass. Built-in equalizer. Fine-tune the sound experience to your taste with a choice of presets and an intuitive equalizer through the Smart Control App. Tailor your sound experience for the level of immersion or awareness you prefer. Our unique Adaptable Acoustic feature offers the choice of either Open or Closed ear adapters, that match with special EQ modes to provide the perfect setting for your exercise. Choose an Open ear adapter style to stay aware of your surroundings but at the same time minimize body-borne noise, like hearing your own breathing or footsteps. Or simply switch to an insulating Closed ear adapter that blocks outside sound for an immersive audio experience.