3-Stage Volume Limit Protection：Midola Kid's headphones use 74/85/94dB 3-stage safe volume, one-click protection (press "DB” button to switch)for hearing health: 74dB mode (WHO infant recommendation) for 3-6 years old, 85dB meets school-age children, 94dB requires parental supervision. Bluetooth 5.4 Headphones(Built-in microphone): 68 hours playtime...