The Gemini™ high security system is a UL rated dimple lock designed to use three rows of dimple pins oriented at 4, 8, and 12 o'clock in the plug. The Gemini™ is one of the few pure pin tumbler locks that is protected against key bumping by design. It offers the building owner full control over field duplication of keys, highly pick resistant cylinders and expanded levels of master keying providing a high level of key system security.