This is a gently used H&S performance mini max race tuner. This tuner will allow you to remove all emissions on the truck. I personally saw 5 mpg increase with using this product. This item is plug and play, no additional purchases needed. It is full unlocked so you can put any mcc custom tunes on it. Bought this item 3 months ago, only reason I'm selling is because I decided to go with efi live since I'm running twins on my lml duramax.