The Sony WF-SP900 is a pair of truly wireless sports headphones designed for active users. These earbuds feature an IPX4 waterproof rating, making them resistant to splashes and sweat, suitable for intense workouts. The WF-SP900 supports a unique charging case that provides additional battery life, with up to 24 hours of total playback time when combined with the case's battery. A standout feature is the dedicated fitness tracking functionality, which helps users monitor their distance and speed. The earbuds use Bluetooth connectivity and are compatible with voice assistants. They come equipped with Direct Access Controls, allowing users to easily manage music playback and calls without needing to reach for their device. The ergonomic design ensures a secure fit, and the sound profile is tuned to deliver clear audio, enhancing the listening experience while on the move.