The regular mouth stainless steel canning lid is made from stainless steel 304, and the removable silicon gasket is made from food grade silicone, the lid and the silicone gasket comply with food regulations and BPA free.
The stainless steel mason jar storage lids/caps are rust proof, would not have rust problem as normal lids made from tinplate.
The stainless steel storage ball canning lid with slicone sealing gaket would seal the jar properly, would not have leakage problem.
The storage lids/caps with sealing silicone gasket can be used properly with your regular mouth jars.