1.Long Time Durable The gel pad for professional muscle stimulator have a long service life, it can be used about 30 times. The shelf life can be lengthen,which depends on the way of use and the means of preservation. We recommend that before using it,clean the skin with alcohol to prolong the life of the product. 2.Comfort and Health Gel pads are made of high quality materials, are very soft and particularly delicate on the skin. In addition, they have the characteristics of a good viscosity, self-adhesive and reusable. 3.Disposable Vacuum Pack Replacement 60PCS Gel pad. It protect the product from dry or lose sticky. To ensure that customers absolutely receive no one has been opened or used. 4.Maintenance Method Before use, make sure the skin stays clean and dry .It was recommend that you clean the skin with alcohol before using it, to extend the life of the product.