This is the Nxt phase of patented Fusion, sock and liner as one, technology. We've taken our lined outer approach to the next level by strategically applying technology to different areas of the foot, for maximum blister protection. The virtually seamless toe closure is actually UNDERNEATH the toeCareA little bit of care can keep your Wigwam socks performing well for years. For best results turn socks inside out before washing. Wash in warm water and tumble dry on low heat. Maximum water temp is 120° F / 50° C. Do not bleach. Use normal cycle setting, set dryer at low heat.