The Smart Sealer has an inbuilt blade that helps you slit open those packing covers. Refer picture for details. The Smart Sealer makes an airtight & watertight seal. So as long as you are sealing plastic & aluminum sheets you are good to go. The Smart Sealer takes longer to seal with a higher thickness of sheets. So pace the movement of the sealer as required. The Smart Sealer seals better with your experience in sealing it. Feel the seal & work your pace to get that airtight sealing! Use the fridge magnet on the Smart Sealer's base to have it handy at all times.