16x2 or 16x4x2. Sixteen microphone inputs that combo as sixteen 1/4" line inputs, Four sub groups, Channels 1-4 have dual stereo RIAA phonograph inputs, Three band fixed EQ (100Hz, 1KHz, 10KHz), Two aux sends per channel, 1/4" TRS balanced outs (L, R, Mono, on bus 1-4). Has port for an additional two effects sends (possibly available here). This is the later version with 100mm ALPS faders! Later version-Best version, 0 5334 OP Amps. Very good #8+ condition with some small scratches on top right of unit, a slight tape residue, and some very minor rack rash. Comes in red suitcase with owner's manual.