DarkSoul Racings new heavy duty Meaty Bones dogbone set for the HPI Baja5b. Made from extremely durable 4130 Chromoly steel, machined to very exacting tolerances, and heat treated for maximum strength. Featuring removable drive pins should one ever get damaged, and for ease of installing the drive cup boots. Do the math HPIs HD dog bones are 6mm shafts straight across and DS Bones are 6.6mm at the ball end , and 9.5mm in the center and are rated at approximately 200,000 PSI strength