Cardboard Tube Marking Guide

Slots to mark lines for three or four fins

Slot to mark rail button lines for three or four fins

3/32", 1/8", 3/16" holes for marking/drilling vent holes

Inner diameters are as follows:

3"CB - 78.6mm

4"CB - 101.5mm

5.5"CB - 140.5mm

*CB is standard cardboard tubing*