Sony MDR1RNC Premium Noise-Canceling Headphones (Black) Precision noise cancelingreduces up to 99% ambient noise Full-auto AINC auto noise canceling function with Dual Noise Sensor technology for optimized performance 50mm Liquid Crystal polymer film diaphragms (5-24Hz) Enfolding structure delivers wrap around comfort and an improved acoustic seal for improved bass response Comfortable ear pads deliver powerful bass response and long-term comfort