This SealerSales W-455AT 18" Automatic Double Impulse Sealer with 5mm Seal Width uses two heating elements (upper and lower) to fuse materials from both sides at the same time allowing thicker materials to be sealed. This sealer is designed for continuous sealing of thermoplastic materials. It is equipped to seal materials up to 18" wide and up to 24mil total thickness. The W-455AT has 3 separate control settings for for sealing time, recycle time, and congealing time. This SealerSales W-455AT 18" Double Impulse Sealer can be operated automatically or manually, and includes electric foot switch and worktable.