Safe, lightweight and sized for kids, the JBL Jr310BT wireless headphones safely deliver up to 30 hours of legendary JBL sound and fun for the youngest music fans. Headphones are designed to never exceed 85dB to protect hearing, with controls that can be easily operated by the children themselves. Kids listen in comfort with custom designed soft padded headband and ear cushions for a soft fit. And every headphone is different as the JBL Jr310BT can be customized with the available, reusable stickers for even more fun! JBL Safe Sound JBL legendary sound designed to never exceed 85dB making them safe for even the youngest music fans. Bluetooth enabled A wireless connection up to 15 meters away means no wires to worry about. Built-in mic Help your kids stay connected to the world with the built-in mic. They can chat easily with friends and family during downtime, or teachers while they’re busy learning. Read Less - Specifications Power supply: 5.0 V 1.0 A Frequency Response: 20 Hz – 20 kHz Impedance: 32 ohm Sensitivity: 90 dB SPL @ 1kHz / 1mW Maximum SPL: 80 dB Microphone sensitivity: -40 ± 3 dBV @ 1kHz / Pa Maximum operation temperature: 45 °C Driver size: 32 mm / 1.25 " Dynamic driver Weight: 115 g / 0.254 lbs Bluetooth version: 5.0