Hamilton Kids-BLU Children's Headphones Recommended for children ages 3 and up, Flex-Phones deliver high quality sound that will never exceed 85 decibels, ensuring young developing ears are protected Certified for all major USA and international child safety testing standards These were awarded the Scholastic Teacher's Pick as "The Best of 2015" Nearly indestructible, made from a single piece of EVA foam (EVA foam is a safe, non toxic, BPA-free, soft, and extremely flexible material) 3.5mm stereo plug | Drivers: 30mm | Impedance: 32 Ohms | Frequency response: 20 to 20,000 Hz | Sensitivity: 82dB | 4 foot straight nylon cord