NT01 is a D.O.T. approved competition radial with an asymmetrical, non-directional tread pattern optimized for dry racing conditions. Originally with a tread depth of 6/32nds", the NT01 can be shaved to 4/32nds" to reveal a "slick" tread surface with two circumferential tread grooves. The NT01 features a racing-inspired tread compound, steel sidewall inserts, and a rayon carcass; all formulated for on-track performance to deliver extreme cornering power for fast and consistent track times. If you need help picking out a tire, or have questions about sizing, please contact us at 1-480-966-3040.