Famous for its lightweight BMX parts, the Fly Bikes Acello TR is a new transition version of the 4.5" length specified by Chase Hawk and Larry Edger. The 4140Cr-Mo(harder than 4130) is CNC Machined to cut out the 4140Cr-Mo (harder than 4130) and has a dent on the top for reduced weight and a thicker bottom that is needed for strength. This design makes the grind area more solid and eliminates faster slides and dents. 3/8" adapter included for front and back use. Sold as a single unit. Material: CNC Machined 4140 Cr-Mo Length: 114mm/4.5" Diameter: 36 mm Weight: 165g/6.80 oz