Just a "normal" key. Autozone required me to provide a bunch of vehicle information to include my VIN, DOM, and mileage before they'd order it. Those were required fields in their computer system. I'm not sure what "flashing" the computer consists of, but I guessing (hoping) mine is received ready to install. Removing it didn't seem like anything cosmic. I'm mostly just wondering if there are any important "special instructions" to bolting it back in. I'm probably over-thinking it...