Yes4All Foam Roller is made of high density, heat sealed foam which is 30% heavier & firmer than the ones from the same class. EPP material can reduce parts, decrease cost and enhance performance. The foam roller's surface is smooth, soft and non-slip for maximum workout performance. The full round shape is high density which is 20% - 30% firmer than other. The firm density core keeps the roller's shape intact, even with the most strenuous workouts. We offer a variety sizes of foam rollers 12", 18", 24" and 36" long by 6" diameter fitting all your fitness purposes. It is designed as an exercise roller wheel to help you maximize your movement on an extreme to enhance balance, core abdominal, back stabilization, body awareness, and dynamic strength. Lightweight and portable. You can stash them in your suitcase when travelling and use it to get a good relaxing time in your hotel room.