Our Underworks Premium Invisible Footlets Are Made For All Day Wear. They Combine Comfort And Reliability With A Super Heel Grip Feature That Is Designed To Stay On And Still Not Show Above Your Shoes. They Are A Combination Of Seamless Comfort, Cotton Blend And Great Invisible Fit. By Choosing Our Cotton Products, You're Supporting Our Investment In Better Cotton's Mission. Better Cotton Is Sourced Via A System Of Mass Balance And Is Not Physically Traceable To End Products. Heel Grip Feature Designed To Stay On!