Ronhill Classic Trackster Running Pants Exertec 100 - Tough, lightweight and with 4 way stretch, this is an incredibly comfortable and soft running fabric that won't distract you while running. Durable Fabric - Hard wearing fabric for long-lasting use. Lightweight And Breathability - Great breathability and good air flow keeping your feet dry during training. Foot Stirrups - To keep the trackster in place and stop them riding up. Inside Pocket - A small interior pocket provides space for a key or small valuable.