myfeet fluid orthotics are insoles that massage your feet as you walk! They contain glycerin, a non-toxic liquid that moves to the unsupported areas of your feet, providing custom support that promotes better posture. What separates us from the rest is the fluid feeling you get from walking on our product. The liquid displaces 80% of the shock to the back, hips, knees, and feet. The glycerin moves back and forth, massaging the foot and significantly increasing the circulation throughout your feet!