A line lock is a manual valve that locks hydraulic pressure in a brake line. Line locks are typically installed on the front brakes of rear-drive drag racing cars to enable easier burnouts. They can also be used to hold a car at the starting line while your feet are busy with the clutch and throttle pedals. To use, simply apply the brakes firmly and turn the lever. When you release the pedal, the affected brake(s) will remain locked until you turn the lever back to the released position.
This high-strength valve (rated to 7500 psi) has 1/8 BSP female inlet and outlet ports. Valve body measures 2 3/4" long x 1" wide x 1 1/4" high. The handle is 4 3/4" long and adds 1 1/2" to the height.