EN 1300 is the European standard for high-security safe locks. The test looks at how many usable codes or key variations a lock has, and how well it resists manipulation, forced attack and, for electronic locks, electronic attack. The result is a lock class: A, B, C or D, from low to high. Key locks, mechanical combination locks and electronic code locks can all be certified.
The higher the resistance class of the safe, the higher the required lock class and the more locks are needed. A lock of a higher class may always be fitted to a safe of a lower class. If you replace a lock, the new lock must have at least the required class. Otherwise the certified resistance class is no longer guaranteed. Which lock class each resistance class requires is shown in our overview of the resistance classes.