All sizes have five-rib tread and STEM-2 technology.The semi-rounded shoulder treatment reduces shoulder tearing and step wear, and provides lateral stability and water dispersion. The RY023T series is designed for city and regional applications and has improved performance and traction.Sidewall abrasion guard reduces damage to sidewall caused by curbing.It also provides excellent lateral stability and water dispersion,RY prolongs the casing life by controlling heat..