Description:  IMPRESSIVE SOUND QUALITY IS THE ULTIMATE GOAL: The High-fidelity stereo sound benefits from the 40mm neodymium driver, CSR chip, and the around-ear cushion design which provide a well-closed and immersed enviroment for your ears, Just lose yourself in the music! NOTE:  headphones is passive noise isolating, NOT active noise cancellation(ANC), it can't cancel the noise completely but it won't drain the battery and damage the sound. 2. The closed-back design provides immersive Hi-Fi sound with CSR chip and 40mm driver together, it is better than ANC in term of sounds quality BUILT TO STAY COMFORTABLE: The Memory-protein ear cushion simulate human skin texture, ensuring lasting comfort. The stainless steel slider and softly padded headband allows you to find the perfect fit without constraint and provide excellent durability NEVER POWER OFF, BOTH WIRELESS & WIRED: 1. The wireless mode: Battery update to 20-hr music time/ talking time in a single charge. A 10-minute charge gives 2 hours of play when battery is low. 2. The Wired mode: you can also use it as a wired headphone with the provided audio cable so the headphones will never power off HANDS-FREE CALL & BUILT-IN MIC: Please Note: The Microphone only works in the wireless mode. Mpow Bluetooth headphones provide a quick and stable connection with your Bluetooth enabled devices like cell phones, tablets, pc, TVs within 33 feet, with a high-quality built-in microphone for hands-free calls FOLDABLE DESIGN WITH A PORTABLE BAG & GENTLE REMINDER: The foldable Headband is not only designed for saving your desk space but for carrying in the provided bag. Gentle Reminder: Depending on your head/ear size/shape, it may be a little tight(feels like"on ear") for someone to wear which is designed to avoid sound leakage. In case of that and to get both audio and wearing comfort, please take off the headphone every 1-2 hrs to get your ears relax and protect them from muggy environment in use Brand Name: STEVVEX Headphones Model Number: ST10S4799GXX Drive unit: 40mm Impedance: 32 ohms Sensitivity: 108dB+3dB Line length: 1.5 meters Frequency response: 20-20K Hz Connection plug: stereo 3.5mm