The fireproof lock is made of high-temperature-resistant materials (such as 304 stainless steel, copper alloy, etc.) and its internal structure has been specially designed to maintain the lock body's strength in high-temperature environments, preventing the fireproof door from failing due to thermal deformation. Its fire resistance limit usually reaches over 90 minutes, and some high-end products can even reach 180 minutes, meeting the requirements of national standards such as GB 12955 - 2008 "Fireproof Doors".