WHAT IS A MASTER KEY SYSTEM? Plain and simple, a master system works like any regular system, but it allows you to have different levels of access to each lock. Wait – what’s a key system level, and how does this whole “master key system” idea work? First off, you need to understand how cylindrical locks work. A master system takes a standard pinning one step further and uses “master wafers” or “spacers” in each chamber. These wafers create an additional shear line that al