Sony MDR-ZX110NC Noise-Cancelling Stereo Headphones utilize 30mm dynamic dome drivers with PET diaphragms and neodymium magnets in a closed-back supra-aural "on-ear" design to deliver an extended low frequency response of 10 to 22,000 Hz with a sensitivity of 115 dB/mW when using active noise cancellation and 110 dB/mW passively. The active noise-cancelling circuit can be turned on and off with an earcup-mounted switch and utilizes a single AAA battery to help reduce ambient noise by up to 95% or 13 dB. The noise cancelling circuit can operate for up to 80 hours when using an LR03 alkaline battery and up to 40 hours when using an R03 manganese battery. The headphones will continue to operate passively when the battery is drained without active noise cancellation. Product Features Noise Cancelling reduces up to 95% ambient noise Swivel, folding design for ultra-portability 30mm dynamic driver unit for clear and rich sound 80 hours battery life (Noise Cancelling on) In The Box • Headphones • Printed documentation • Requires 1 x AAA Batttery - Not included