The POWERTRAX® Grip Lok is the latest design in traction adding differential technology. It combines the fully automatic locking action of our traditional locker, with the strength of a fully machined case. Using our automatic locking technology, the POWERTRAX® Grip Lok delivers automatic mechanically actuated traction. This is our strongest locking differential, offering the ultimate in competition and off-road capabilities. The POWERTRAX® Grip Lok comes fully assembled. Because there are no friction plates, so you can use any gear oil you like, including full synthetic and racing lube. And don't forget that there is no friction modifier additive necessary! Designed for rugged competition and off-road traction needs, this is not for the timid or weak! POWERTRAX® TRACTION SYSTEMS are the ideal solution for just about any light truck, sport utility, and muscle car on the road today. Whether you need the safety of added traction for daily commuting, recreation, work, or just so your muscle car puts power to the pavement instead of burning one wheel up, the POWERTRAX® TRACTION SYSTEMS are your answer.