MTC Grade B Rating
Certain types of computer media (CDs, DVDs, USBs, and memory sticks) are less sensitive to heat and humidity than tapes, cartridges, hard drives, etc. These less-sensitive items can be safely stored and protected inside some products that are designed to protect paper records.
Products that carry the MTC – Grade B rating have been tested and certified to protect these items. Products that are rated Class 125 (Data Safes) are designed to store and protect all types of computer media, and should be used whenever the more sensitive items need protection.