Technical Specifications : Bluetooth Chip : JL Sensitivity : 853dB @ 1KHz Bluetooth version : V5.0 Battery : "3.7V, 350mAh, Li-ion polymer battery Frequency response : 20Hz-20KHz Charging time : Approx. 2 hours Play time : Up to 22 hours at 80% volume Charging Port : Micro-USB Operation Distance : 10 meters (without any obstacles) Speaker type : ?40mm 32 This product will be auto turn off under below FOUR conditions: 1. Turn on headphones but not pair with any device for over 3 minutes. 2. Turn on headphones and paired with device, but not use it for music playing or phone call for over 15 minutes. 3. Plug in 3.5mm audio cable to the jack, BT will be auto off. Can use the product as wired headphones. 4. Plug in the USB charging cable for power supplying, BT will be auto off for charging. Bullet Point : Best Suits for Kids Ear 100% Safe and Ear Comfortable Active Noise Cancelling technology. Significant noise reduction for travel, work and anywhere in between. Advanced active noise reduction technology quells airplane cabin noise, city traffic or a busy office, makes you focus on what you want to hear, enjoy your music, movies and videos. The noise cancellation function can work well both in wire and wireless mode. Proprietary 40mm large-aperture drivers. Deep, accurate bass response. The Active Noise Cancelling around-ear headphones from ePitchPerfect (ePP) give you crisp, powerful sound and quiet that helps you enjoy your music better. The goal that provide Customers with better sound quality, is our constant pursuit. 30 hours playtime per charge at Bluetooth mode. A built-in 750mAh battery won't allow your headphones power off, you can enjoy your world without noise for 30 hours' long time. Don't need to worry the power shortage problem on the long travel. 18-month warranty and quick response friendly customer service. Dedicated customer service team, provide you with quick response and friendly customer service, which will always serve for you and certainly satisfy you. The professional protein earpad and 90 swiveling earcups. More durability and comfort, Enjoy high-quality, Long-listen comfort. Skin texture, lightweight comfortable around-ear fit you can wear all day long. Gentle Reminder: please take off the headphone every 2-3 hrs to get your ears relax, in order to get better hearing enjoyment, and keep the head comfortable.