A spare battery: When does the white noise machine stop playing music after shutdown? Our upgraded white noise machine is equipped with a 1800mAh, 6.66Wh (47.1 grams) rechargeable battery, which can provide up to 10 hours of playtime to help your baby fall asleep and sleep longer, whether during naptime or at night. Noise protection: Twenty-four high-fidelity sounds (lullaby, natural music box sound, birth sound, humming, brook sound, white noise, humming, fan sound) allow you to choose the ideal background to block out distractions and create the ideal environment for work, study, sleep, or a restless baby. Small colored night lights: A soft and adjustable LED lamp can provide abundant but less dazzling light to your room at midnight. There are also 7 RGB color ambient light products - steady or breathing rhythm - ready to meet your personal preferences. Simple Setup & Auto-Off Timer: No two functions share the same button. Even in the dark, it's easy to adjust and change settings or