The Twin Mill III is a Hot Wheels casting designed by Josh Henson that debuted in 2008 New Models. Twin Mill III features two large engines on opposite sides of the car. The front-end of Twin Mill III resembles the front-end of Twin Mill. It has two triangle-shaped headlights. More of the twin engines is visible on the sides of the Twin Mill III. Somewhere between the end of April 2012 (Base code E17) and the end of May 2012 (Base code E21) the mold for the engines was slightly altered. The little dots on the sides of the engines are now gone; the side of the engines is flat (see Gallery).