The biscuit is pretty simple to set up, the biscuit should be at 90 degrees to the arrow and the arrow should be at 90 degrees to the string. The arrow should fit loosely in the biscuit. Use the correct spine arrow, too light a spine and the arrow may bend at the release and cause a tuning problem. This rest sends the arrow off real straight so the arrow doesn't need a lot of helical to correct its flight. A correctly spined arrow with straight fletch or a slight offset will fly just fine off this rest. The aluminium biscuit has a .36" hole and the ICS carbon biscuit has a .32" hole. If you are setting up a kids bow with skinny aluminium arrows you could still use the ICS carbon biscuit. The aluminium biscuit will give a loose fit with arrows up to 22xx, and if you want you can still shoot the carbon arrows with it. The same biscuit that I used last fall to shoot my deer, works today with a heavy fishing arrow. This rest is accurate, quiet, durable, and dependable.