[What's it for?] Hydrogel gel sheets, accessory for Abdominal Toning Belt, EMS AB Trainer, Waist Trimmer Belt, ABS Toner Body Muscle Trainer, ABS Stimulator. [How long can the gel sheets last?] The gel pad needs to be replaced regularly; each pad can be used 20-30 times. [How to maintain them in a right way?] Clean and dry your skin before use. After using, stick the gel sheets back to the cardboard. Gel sheets are consumables. Replace with a new sheet when: 1. You notice a decrease in conduction performance, resulting in reduced strength. 2. The pad loses adhesiveness, the gel surface dries out, or there is damage or dirt that cannot be cleaned. How to use: Attach the side with the white paper to the device. Attach the side with the protective film to the skin. Color: Blue Material: Hydrogel Size: 4 x 6 cm Package Contents: 48 x ABS Trainer Replacement Gel Sheets Note: Only the items listed are included. Other products are not included. Lighting and display differences may cause slight color variations between the image and the actual item. Measurement error allowed is +/- 1-3 cm.