Dual-sided Design: The Smooth (Plastic) Side for Most Carpets or Other Blanket(not all surfaces), and The Foam Material Side for Most Hard Floor, Wood or Tile(not all surfaces). Generally Speaking,Only Use The Plastic Side Down For More Smoothly. The Foam Side Has a Cushioning Effect, When Your Hands or Feet Press on Foam Side to Workout, It has a Protective Effect on Your Wrists. Build Up Your Strength Before You Add This. So You Can Hold The Position Effectively and Safely. | NOTE: When You Use The Plastic Side Down, The Plastic Side of the Core Sliders can Easily be Scratched and Scratch Your Floor. Because of The Material Problem, All This Kind of Exercise Sliders on the Market have this Problem,You Can Try Use it on a Different Surfaces,Such as Carpet, Blanket, Exercise Mat, or Put a Blanket on Your Workout Mat and so on, and also If You Find that Foam Side Slides Very Easily On Your Floors, You Can also Use The Foam Side Down to Workout. | Two Sliders in a Set: 2 x Dual-Sided Core Sliders (7" in Diameter), Premium Quality, Durable, Lightweight and Portable, Ideal for Worldwide Travel | Very Fun: Simple and Comfortable to Use the 2 Core Sliders, Your Hands or Feet Never Leave The Floor, Which Offers an Incredible Core Workout Low-Impact&Weight-Bearing Exercise. Great for Building Your Core&AB Strength, Range of Motion and Stability. | What You Get: 2 Premium Core Sliders, Simply Illustrated Workout Guide with 12 Exercises, Our Worry-Free 12-Month, and Friendly Customer Service--Customer Satisfaction is Our First Priority. If You Don't LOVE Our Core Sliders, We'll Refund Your Purchase.