The GoFit(R) GoSliders are designed with a low-friction, non-marking, material to slide smoothly on soft surfaces. Challenge yourself by increasing stability, toning your core, arms, and legs. GoFit(R) Yourself Low-friction sliders with non-marking material to slide smoothly on surfaces Slider booties included for use on hard surfaces Firm, foam grip pattern on the top side, means ideal traction for hands and feet