Long Battery Life - The M20 Bluetooth earpiece has a built-in 220mAh rechargeable battery, offering 8-10 hours of music playback or calls on a single charge, and fully charges in just 1.5 hours. Easy Operation - Power on/off with a 3-second long press, single click to play/pause or answer/hang up calls, long press for 2 seconds to reject calls, and double click to redial the last call. Use the "+"/"-" buttons to skip songs or adjust the volume. Left/Right Ear Wearing - This Bluetooth earbud can rotate 180 degrees for either ear. Its earhook design and soft material ensure comfort for extended wear, making it suitable for activities like sleeping, walking, or working. IPX5 waterproof/sweatproof rating makes it ideal for gym workouts. Universal Compatibility - This Bluetooth headphone works with most Bluetooth-enabled devices, including smartphones, tablets, and laptops, and can connect to two devices simultaneously.