Model No. HP/NC-II. Great for airline travel or home theater use. Dual prong in-flight adapter plug included; 50 Hours of use with two AAA batteries (not included); Single entry cord; Travel pouch included. Improve your listening experience in a noisy environment. Noise cancellation headphones reduce unwanted background noise which allows for a quieter environment to enhance your audio entertainment. Tech Talk On How It Works: Microphones inside the headphone listen to the noise that is sent to your ear and distorting your music. Information from those microphones is fed to the audio enhancer pack where it is analyzed, and a precise active noise cancellation wave is generated. When this anti-noise wave meets the unwanted noise, the noise is reduced and your music comes through loud and clear. Features: Maxwell's noise cancellation technology is incorporated into our HP/NC-II headphones for automatic noise reduction; Reduces over amplification distortion; Lowers non-linear distortion; Reduces frequently response variability; Improves frequency response; Digital-ready stereo headphones; Comfortable, lightweight and easy to adjust; Collapsible and compact for portability and easy storage; 50+ hours of battery power with 2 AAA batteries (not included); Dual prong adapter for portable and in-flight entertainment systems; Includes a drawstring travel bag for easy storage. Specifications: Frequency Range: 20 - 20000 Hz; Active Cancellation: 20 - 1500 Hz, better than 15 dB between 150 - 300 Hz at maximum cancellation; Headphone (only) Weight: Approximately 3.7 oz; Cable Length from Sound Pack: 34 inches; Power: 2 x 1.5V (AAA) Alkaline Manganese Batteries - battery life of 50+ hours. Limited 90 Day Warranty.