WHY YOU WILL LIKE THEM The SpeedRoll technology with a nylon plate is stiffer and provides more support to the midfoot. The nylon sheet is more versatile to accommodate a wider range of speeds and temperatures. The PWRRUN PB foam is a unique blend of perlite PEBA foam, which is more durable and stable, making it responsive and cushioning every step. TECHNOLOGY determination: races/speed runs cushioning: PWRRUN PB insole: SRS (SUPER RESPONSIVE SOCKLINER) drop: 8mm (36/28 mm) UK sizes: 3-10 WEIGHT women 206 g