The 2021 Tour Series discs feature the new Metallic Z plastic. Heat - Distance Driver: Speed 9 | Glide 6 | Turn -3 | Fade 1 | Stability 0.0. The Heat™ debuted as the 2014 Ace Race proto and quickly caught fire with players for its control, glide and distance at slower arm speeds. It has a smaller rim for easier grip, and is being hailed as a breakthrough in delivering improved distance for new and developing players.