As your feet face the elements, the Outdoor Series tetratsok is an interface system specifically designed to perform and adapt to any type of terrain. Engineered with AIS:technology and constructed with Injinji’s exclusive natural wicking Nüwool™, the tetratsok provides exceptional comfort and performance unlike any other athletic wool sock.

Anatomical Interface System (AIS) is engineered to separate your toes with a thin, anti-friction membrane that is both lightweight and breathable. Seamless in construction, the tetratsok forms to every contour of your foot. This allows for true restriction free movement from your heel to five toes, encourages healthy circulation, and eliminates skin on skin contact between your toes to prevent blisters from developing.