GDW - Premium Golf Graphite Shaft Extender Oversize .535x.600" New Stronger Durable and Lighter Design - .535" insertion .600"OD Extend Graphite Golf Shafts* Military grade nylon plastic with fiber reinforced material Specially engineered epoxy bonding pillars for Strong Epoxy Adhesion Easy to Install - Superior Quality and Design - MADE IN U.S.A.