2 Option Slots that fit any combination (up to 16 analog ins and outs) 8 AES/EBU I/O (on DSub 25), 8 ADAT or 2 SPDIF I/O (on TOSLINK), RAVENNA - AES67 I/O (on RJ45), SYNC - LTC/MTC/VideoRef/Wck (requires CON-D15-VTC cable), 2 slots for AD8D/AD8P, DA8/DA8P and MADI option cards, AC or DC power connections, Detachable rack ears for placement in a standard rackmount