Made Of High-Durability Medical Silicone Of Excellent Quality. It Provides Even Pressure Distribution Thanks To The Different Silicone Density. The Blue Silicone In The Center Of The Heel Is Softer In Order To Support The Heel Spur. It Relieves Pain And Reduces Pressure On The Joints Of The Spine And Achilles Tendon. It Provides Maximum Support For The Heel And The Heel Spur.