Boost Metabolism the Natural way! The Metabolism Booster Massager is a non-invasive fat burner that can be used anytime and anywhere. It has the ability to reduce muscle soreness, increase metabolism and blood flow. How to use: Material:Silicone Input Voltage:0.85V Working Voltage:3.2-4.2V Rated Time:15 Minutes Input Current:25mA Size:44mmx10.5mm Package Included:1 x Metabolism Booster Massager