This is the Du-Bro XL Prop Balancer Shaft. FEATURES: This extra long shaft replaces the stock shaft on the #499 Tru-Spin Prop Balancer (DUBQ0130) Accomodates longer spinners, props, heli rotor heads, and more Steel construction INCLUDES: Du-Bro XL Prop Balancer Shaft SPECS: Max Diameter for Propeller Hole: 19/32", .5938" (15mm) Length: 8" (203mm) jxs 08/09/12 ir/jxs