Safe products must provide appropriate functionality to meet your storage needs and wants. Since its founding, Liberty Safe has been a leader in the development of gun safe functionality. All full-sized Liberty and National Security products come standard with our 3-in-1 Flex™ interior. The top self is available only in safe models 50 cf and above. Designed and implemented in 1998 (and patented in 1999, U.S. patent No. 6,042,207), this unique system includes adjustable shelving and shelf covers, allowing consumers to configure storage space in four different ways: