MBox Pro 3. Very good condition, used it for four years. Everything still fully functional. The Mbox 3 Pro from Avid is a high-quality audio interface that delivers premium-quality audio in a sleek and durable design, ideal for home and project studios. The interface is designed by the same engineering team behind Pro Tools|HD systems to ensure excellent performance and connects to a Mac or PC via a FireWire connection for fast data transfer. It supports audio rates up to 24-bit/192 kHz. Connectivity provides four microphone inputs with 48V phantom power and high-pass filters. The box also has four 1/4" line inputs, as well as two RCA and a single 1/8" (3.5 mm) stereo mini Alt line input for added versatility. A set of six 1/4" line outputs lets you connect up to three pairs of monitor speakers. Using a breakout cable, stereo S/PDIF digital I/O connectors allow you to connect digital audio devices, MIDI I/O connectors provide compatibility with a variety of controllers and devices, while Wordclock I/O connectors let you connect to an external clock device for perfect syncing.