Cardone 30-3891 Remanufactured Ignition Distributor Automated test equipment verifies signal strength, correct polarity of wire harness, air gap and coil performance Precise machining tolerances prevent oil leaks, poor timing, setting of "check engine light" and premature failure Gear hardness determined by application so as to not damage or pre-maturely wear out related components All electronic modules are 100% tested to ensure full functionality Every unit is 100% tested to ensure quality and reliability