ON/OFF switch (A) controls the power to the monitor console.
HI/LOW switch (B) places monitor into HIGH range for monitoring 16
to 145 seeds per second or into LOW range for monitoring 2 to 16 seeds
per second. The HIGH range is typically used for soybeans and other
volume-metered seeds or small seeds. The LOW range is typically used
for corn.
Tuning knob (C) sets the alarm point for seed output on all
rows.