This is the Big three kit. What this does is get all the posable power out of the stock alt. You get three wires (get it, BIG 3) you get a new 4ga wire from the battery neg to the fender, new 4ga from the alt case to the battery neg, and a new 4ga wire with fuse and fuse holder that goes from the alt to the battery positive. this will help with the dimming headlights or issues when installing a big sterio in your car.