Philips NC1/27 Fidelio Noise Cancelling Premium Headphones with Ergonomic Memory Foam Cushions and Compact Multi-Way Folding for Easy Travel, Black Optimized 40mm neodymium drivers for high fidelity sound Standalone acoustic chamber for sound precision 30 hours of ANC play time and unlimited music and talk time Zero hiss to ensure uninterrupted enjoyment Ergonomic deluxe memory foam cushions for long-haul comfort