This is a Hot Bodies Mega Travel Drive Shaft Set for the HPI Savage X, XL, 25 and SS trucks.  This includes two drive shafts, one for each side.  If you upgrade shocks and/or suspension arms on your Savage, you may want to use these to prevent the dog bones from falling out when the shocks are fully extended.  When you have a high-travel suspension system on the Savage, the stock dog bones often fall out quite easily.  The Mega Travel Drive Shaft Set helps fix this problem.  These are a must for hardcore Savage owners.