Our shielding (shielding “S”) ESD aluminum seal protection bags offer optimum protection for your product against electrostatic charging inside and outside the ESD protection zone (EPA) and also function as excellent moisture protection with defined water vapor permeability. The seal protection ensures that once the bag has been closed (taped shut), it can no longer be opened without it being permanently visible. As soon as the seal is broken, a residue with the word “opened” appears, indicating that this bag has already been opened after it was first sealed.