Double-sided to ensure a great workout no matter where you are. Use the foam side on hard floor, or the plastic side for use on carpet! Intensify your favorite moves such as lunges, planks and bridges by introducing a balance challenge. Strength and Condition your entire body with a low impact weight-bearing workout since your body is in constant contact with the surface. The Synergee core sliders come in four different colours to suit your style. Each slider measures 7"x7"x.05", the perfect size for everyone!