The electromagnetic inducted Aluminum-foil at the top of the flask, which is under the inductor, then brings about super-audio eddy current, and it reaches a very high temperature in a jiffy, so as the attached cellophane that it melts to make the two fuse up together. This lets a streak of cellophane on the surface of the Aluminum-foil melt and cement with other materials, as to reach a sealing effectiveness with high speed and high quality. ASK FOR MORE DETAILS