You’ll be excused for being initially confused about the RME Fireface UC USB.
Its predecessors, Fireface 400 and 800, were FireWire devices; but the Fireface UC is a USB 2.0 device.
What it does offer in return is USB, ADAT, S/PDIF and 1/4-inch analog I/O, along with word clock and MIDI protocols. The front offers dual XLR 48 V mic/line inputs along with dual 1/4-inch instrument/line inputs and a headphone output and channel gain control.
Digital channels top out at 192 kHz.
The rackmountable Fireface UC is Windows and Mac OS X compatible and should work with major DAW programs.
RME is a veteran German company that makes its own branded pieces and once ghosted for other better-known brands.