Our best educational headphones include a switch to choose between mono or stereo signal volume control for sensitive ears and extra durable. Each headset has an individual volume control which allows children to easily alter the volume of their headphones when necessary. They feature 2.5m coiled cable and has 3.5mm nickel plated jack and includes 6.3mm adaptor. Technical Specification:Impedance: 32 Ohms +/- 10%Sensitivity: 115dB S.P.L. at 1kHz +/- 3dbFrequency response: 20 - 20kHzMax. Input Power: 30mWAudio output: Stereo/Mono