Get your practice on track! Increase your filing space 50% to 75% without using up valuable floor space. This track storage system features the Stak-N-Lok™ space-saving filing solution, which offers locking doors for added security and privacy (HIPAA). The track assembly is attached to the base of rear stationary units (all tracks are 17-1/2"D). Please allow an additional 2" on end of each side for carriage over-travel.