The Central Tools Brake Rotor/Ball Joint Set, No. 6450, is designed to measure both rotor run-out and ball joint wear quickly and easily. Locking pliers mount securely to any convenient object and the flex-arm makes it simple to position the indicator for taking measurements. By mounting the locking pliers on the spindle, users can eliminate vibration problems and false readings. The 6450 can also be used to check gear backlash, valve guide wear and camshaft wear among other uses.