Bluetooth connection If you prefer wireless listening, this portable MP3 player supports Bluetooth 5.4 for stable transmission with low interference. You can connect to Bluetooth headphones or Bluetooth speakers and enjoy your music without wires. Please note that the Bluetooth function only supports connection to Bluetooth headphones and Bluetooth speakers. Storage and formats This MP3 player supports expansion with up to a 128GB memory card (not included), allowing you to store a large music collection. It supports formats including MP3, WMA, WAV, APE, FLAC, AACLC, M4A, OGG, and more, so you can put your favorite songs in and create your own music space. The builtin 500mAh battery charges in about 2 hours and provides up to 48 hours of battery life. Multifunctional This HiFi MP3 player is not limited to music playback. It offers practical features such as calendar, stopwatch, alarm clock, FM radio, pictures, e books and more. It can be a versatile gift for children, family or friends. HiFi sound quality Built with quality speakers and a powerful sound decoding chip, it restores the original HiFi sound quality for an enhanced listening experience. It also includes a 3.5mm headphone jack for private listening with headphones (not included). The recording function preserves sound quality and clearly reproduces human voice. Use scenarios Daily commute or workouts: pair with Bluetooth headphones for cable listening on the go. Travel or holidays: use the FM radio and memory expansion to keep entertainment without relying on streaming. At home or school: enjoy fidelity music through the builtin speakers or private listening via the headphone jack, and use the calendar, alarm, or e books for convenience.