What Yamaha has to say:
Simple compact headphones that let you enjoy professional-grade sound quality
Product Specs:
Driver TypeDriver UnitImpedanceMaximum InputSound Pressure LevelFrequency ResponseWeight (with Cable)Cable LengthConnectors Headphones / Earphones Driver Type Dynamic, closed back Driver Unit Φ38 mm Impedance 35 ohms Maximum Input 1,000 mw Sound Pressure Level 103 dB Frequency Response 20 Hz - 20kHz Weight (with Cable) 133 g with cable Cable Length 2.0 m Connectors 3.5 mm (1/8") stereo, 6.3 mm (1/4") stereo