If you need to tap in to factory ECU wires - avoid damage to the expensive factory wire harness by using this jumper harness. Factory-style connectors install between the factory engine wire harness and ECU. Splice connections to piggy-back fuel computers, gauges, etc. can be made with out permanent damage to the factory wire harness. Includes ECU A, B, C, and D connectors. 8" long leads. Not required for ScienceofSpeed aftermarket ECUs.