The secret of INTERCEPT technology is that corrosive gases are bonded before they are able to form a bond with the metal in the coin. This molecular process takes place immediately as the coin is placed in the holder. The highly porous copper particles in the INTERCEPT holder & cases embedded in the plastic compound bond to the damaging gas molecules in the air, locking them away permanently. Unfortunately, there is no process to restore corroded coins, which is all the more reason to recommend INTERCEPT's patented coin protection technology from the start. From 2x2 Quadrum Intercept Snaplock Holders to Certified Slab Cases to Storage Cases - there's an INTERCEPT product for your entire collection!