Two Extremely Durable Glider Discs by Poly J (Set of 2 x Exercise Sliders) &ndash; Workout Your Core Muscles by Sliding or Gliding The Dual Sided Discs on Hardwood or Carpet. RELIABILITY  Made from high quality and extremely durable materials. Samples of Gliding Discs were inspected and tested by Poly Js staffed Certified Reliability Engineer in a controlled environment here in the USA. Our Engineer actually tested our product by running it over with a 2 TON vehicle! And to ensure repeat-ability, we ran it over 50 times! CORE MUSCLE  The sliding discs will provide compound exercises to build 6 pack abs and trim those waist lines. WORKOUT ANYWHERE  Sometimes those long vacations can reverse your hard earned muscles. These sliders will ensure that you keep and build those muscles anywhere you go. No more excuses. PUSH, PULL, LIFT, AND PERSEVERE  Poly Js motto, and you can do this with just two of these sliders to target individual muscle groups. DOUBLE-SIDED Fabric side for hardwood floors and hard side for carpets.