Fit for running, pure and simple. Created for winter running, it was designed to cover the widest possible temperature range, from cool days to below zero, when total wind protection would also be ideal. Simple in appearance, its clean lines actually hide a great deal of technology.

Three different types of fabric were used for these tights, to provide the right protection for every part of the body. The front, from the waist to the knee, is made with Castelli's Core Due fabric, a dense-knit, heavier-weight polyester/nylon blend that blocks most of the wind. The polyester part is against the skin for active push-pull breathability and the yarns are hollow core, meaning with a dead air space in the center for additional insulation. On the back of the thighs and glutes, a highly elastic fleece fabric promotes fit. From the knee to the ankle, Castelli's Thermoflex fabric offers perfect warmth and elasticity, while the single seam on the inside of the leg prevents chafing around the knee.

The tight is finished with a raw-edge flat opening at the ankle, flat-knit braces, and a KISS Air2 liner.