This is a Diablosport chip I pulled out of my 03' Cobra. I didn't know my Cobra had a chip until I used my SCT Xcal and had to pull the kick panel because I couldn't flash the computer. The pulley is an unknown make and size, but came off of the stock Eaton. The car when I purchased it had the stock pulley guard still on so the pulley will fit under it if you want a stealth look. I don't need these any more and are collecting dust. No reasonable offer refused and buyer pays for shipping.