The use of the correct bushing set on your pen mandrel makes pen making and turning project kits an easy process. Simply use the bushings on the mandrel as a reference to turn your blanks down to the correct diameter. Used on Rollester Gunmetal Pen Kit: 102992, Stratus Black Enamel Click Pen Kit: 103013 and the Diva Charm Aurora Borealis Pen Kit: 104337.