The length of the sides of the headband can be adjusted to fit your head perfectly. Foldable for storage in your bag, compatible with all audio and video players with jack input. Frequency response: 10 to 24 000 Hz, Impedance (acoustic resistance): 150 OhmsTo protect your hearing, the power of the headphones has been limited to a maximum of 100 mW, Sensitivity of 85 dBPractical foldable design. Compatible with Sony PSP, PlayStation VITA, Nintendo DS and Nintendo 3DS. Very lightweight.