M-Audio 1814 FireWire sound module. FireWire cable included (no power adapter). Digital I/O: ADAT optical in and out switchable to S/PDIF optical, co-axial phono S/PDIF in and out (both S/PDIF outputs support AC3 and DTS formats), MIDI In and Out, two six-pin Firewire ports, word clock in and out (will sync to external word clock at sample rates up to 96kHz).
eBay