GMS Universal Line Lock Kit (C4, C5, and C6 Corvettes)This GMS Line Lock Kit can be a key element in insuring a serious racer's success. In order to do well at the track, the number one thing you need is traction. In order to get traction, your tires need to be hot. In order to get your tires up to temp, you need a Line Lock Kit. This line lock kit allows you to lock either your front or rear brakes. When you're sitting in the staging lanes, you can lock your front wheels with the flip of the switch.