This is an optional HPI 18x116mm Super Heavy Duty Drive Shaft Set, and is intended for use with the HPI Baja 5B, 5T and 5SC. Seriously beef up your Baja drivetrain with these Super Heavy Duty Drive Shafts. These are thicker diameter than the stock drive shafts, specially designed for extreme driving and high horsepower engines. These are included as standard equipment on the Baja 5SC and 5SC SS but are excellent optional parts for the Baja 5B, Baja 5B 2.0, Baja 5B SS and Baja 5T that will dramatically increase the longevity and strength of your drivetrain.