This is just one of over 75 professional audio mixers covered in The Mixer Output Guide, which describes direct outs, inserts, hidden mods and more. To see the rest, and for definitions, visit The Guide.
Direct Out:
Stock with 8 XLR male outputs, expandable to 48 out (multi-use as direct outs, aux, main, group, matrix), switchable pre/post fader
Insert:
Stock with 8 XLR male outputs, expandable to 48 out, stock with 48 in (multi-use as direct outs, aux, main, group, matrix), switchable pre/post fader
Gain Control of Direct Output: