Maxell's patented ceramic coating process acts as a protective armor for the fine metal particles in the magnetic layer of the tape to guard against heat, humidity, abrasion & oxidation. The process is skillfully engineered to achieve the high output, high S/N ratio & low error rate necessary to ensure reliable data storage across a wide range applications. All 4mm tapes feature Maxell's unique Safe-T-Lock hub-locking mechanism to ensure proper tape tension & prevent miss-threading during initial loading.