Operation Steps: (1)Press the knob to turn on the heat sealer; (2)Turn the knob to "+" to seal bags; Press the small button to switch modes. Here is the order: ①mode for super-thin bags ②mode for common bags(Daily use for sealing bags) ③ mode for pro thick bags. (3)Turn the knob to "-" to cut open bags. (4)When do not use this plastic bag sealer, please adjust the knob to the middle area between "+" and "-" in order to lock it and avoid product damage due to unexpected heating. Package Included: 1*Bag Sealer 1*Instruction Manual 1*Practice Bag 1*USB Cable