When you are looking for a whisker biscuit, you should always consider your arrow's size. The smallest one has an 0.30-inch inside diameter and it is suitable for A/C/C carbon arrows, 17XX or smaller aluminum-shaft arrows, carbon or Axis arrows, as well as Outserts.
A medium whisker biscuit has a 0.320-inch inside diameter and it is an appropriate choice for 19XX or smaller aluminum shafts, and internal-component carbon arrows. The large models have an inside diameter of 0.395 inches and can be used for 23XX or smaller aluminum arrows.
Whisker biscuits for bow fishing have a 0.360-inch inside diameter and are suitable for unfletched fishing arrows.