This factory upgrades use the OEM fuse block & TXL High Temp wire for bullet proof performance. 10106 uses the factory bulkhead connector so no special brackets or fabrication are required to make it fit to the fuse block. Open ended wire leads allow for custom routing of wires. This kit include standard 12-circuit features. Also includes additional GM pre-wired plugs for: Ignition Switch, Dimmer Switch and Turn Signal.