Plunger buttons are a fairly sophisticated tuning aid that can help you correct any slight mismatch between the draw weight of your bow and the spine of your arrows. They actually have two purposes. The first is to position the arrow shaft relative to the string and riser. With the advent of metal risers with true centre-shot capabilities, this arrow position is critical. The second is to let you adjust your horizontal grouping relative to your sight picture.

If you are a beginner, it is best to stay away from plunger buttons until you are completely comfortable with your bow, have determined your draw length and draw weight, have selected an arrow for your bow, and have mastered all the other adjustments your bow requires. Regardless of your experience level, you should never try to use plunger button adjustments to compensate for an arrow that is not the correct spine for your bow.