The Power Rack Memory Locks have a tab that fits exactly into a recess on the Gibraltar rack bars. In this way, the memory locks not only fix the desired distance, the rack rod is also always in the same direction of rotation, which increases stability.
GIBRALTAR Memory Clamp SC-GPRML Features: Memory Clamp for Gibraltar rack bars Material: Metal Diameter: 1-1/2" (38,1 mm) 2 pieces Fixation with standard tuning key (square)