Rubber Outsole.
Product Story In Pwr Xx Nitro, The World Is Hers. Pumagrip: Durable Performance Rubber Compound Designed For All-Surface Traction Low-Cut Boot. A Lightweight, Nitroâ¢-Infused Midsole Offers Superior Cushioning And Responsiveness, While The Pumagrip Outsole Provides Multi-Surface Traction, So She Can Feel Secure, Locked In, And Grounded For Floor Work Movements And Light Work On The Treadmill. This Trainer Was Designed Specifically For Women, With A Supportive, Stylish Silhouette That Stays Secure And Locked In While She Sculpts, Sweats, Or Crushes Cardio.