NZXT Lexa S - Manual (Page 14)

NZXT. 12
2. Remove heat sinks easily through the CPU punch-out on the
motherboard tray
Dual Fan control
Behind the front panel there are two knobs for fan control. The left
controls dual intakes from the front 120mm and side 120mm while
the right controls dual exhausts out the top 140mm and rear 120mm