The FlexLock wall system is mortarless and groutless. Because of its masonry nature, the system also retains the engineering properties of a traditional block wall. The system has fire characteristics similar to an ungrouted traditional block wall and flexure similar to a mortared post-tensioned wall.

To eliminate the mortar and grout from all the courses above the first one and still retain structural strength, FlexLock designers used three key elements. First, it employs a geometric design with male and female mating surfaces on both the head and bed joints. Second, there is a tight joint fit tolerance created by a machined bearing surface on each unit. And third, a post-tensioning vertical anchor system is used. The result is a load bearing system. No other load-bearing masonry wall system is being marketed this way.

The key aspect of the system's performance requirements is the tight fit tolerance between each block course, except the first course when masons lay the block and fit them into the lower course with mortar. The block's machined surface eliminates the roughness normally found between traditional masonry block courses.