Touch and hold the front button for about 3 seconds until you hear the beep sound twice. Then, TOWNEW T1 will seal the bag for you. In case you have overflowing trash on your TOWNEW T1, TOWNEW T1 also has an Overflow feature where the top compartment will be lifted up to fully wrap the overflowing trash without any spill or leak and then seal it. Wait until the sealing is complete, and then take the trash out. After that TOWNEW T1's top compartment will be closed automatically and install the new bag for you.