This is a USB microphone and audio interface made by Classic Pro. * Plug & Play compatible (no drivers needed) * Real-time headphone monitoring function * 48V phantom power switchable (red/blue LED indicator) * Noise reduction technology * Microphone/headphone volume adjustment buttons Compatible OS: Mac OS9/OS X, Windows 98SE〜7 *Operation on the latest OS is unconfirmed.* Brand new, unused, and unopened. There are some minor scratches on the package, but the product itself is unused. --- Specifications (from the package) * Frequency Response: 20Hz〜20kHz * Sampling Rate: 48KHz / 44.1KHz * DA Converter: 16bit * Headphone Impedance: 32Ω * Phantom Power: 48V --- Included Items * Main unit (CAI16U) * Package (outer box)