What is the function of liquid insole

Liquid insoles are usually filled with glycerin，so that when people walk, the liquid will circulate between the heel and the sole of the foot, thus forming a friction effect and effectively releasing the pressure on the foot.
The liquid insole can be placed in any kind of shoes. It can relieve fatigue or pain caused by standing or walking for long periods of time.
Liquid insoles can be used multiple times, just wash them in cold water and dry them naturally, leaving them clean again the next day.