The red Sony WI-C300 are wireless in-ear headphones designed to deliver extended listening time and lifestyle convenience for music lovers and audio aficionados relaxing, traveling, or studying inside or outdoors. Their 8.9mm dynamic drivers utilize neodymium magnets and produce a wide frequency response of 20 Hz to 20 kHz. The behind-the-neck design won't interfere with comfort or ease of use. Bluetooth version 4.2 and NFC technology grant simple and effective wireless integration with your mobile device.The built-in rechargeable battery affords up to eight hours of listening time or up to 200 hours of standby time via a full charge. Thanks to the in-line remote's integrated microphone and buttons, you can take calls and control playback without accessing your smartphone. Compatibility with voice assistants unlocks smooth voice-based commands. The WI-C300 headphones include multiple eartips and a micro-USB charging cable.