/ Middle Atlantic 9 SPACE SLIDING RAIL SYSTEM, 250 LB. CAPACITY Middle Atlantic SRS4-9 9 SPACE SLIDING RAIL SYSTEM, 250 LB. CAPACITY Middle Atlantic SRS4-9 This Middle Atlantic SRS Series 19", Sliding Rail System SRS4-9 is the perfect solution for in-wall and millwork mounting, or other set-ups that require convenient pull-out access to equipment. The rack can be pulled out a full 19 inches ,to provide rear access to components with shallow depths. Ball bearing slides ensure smooth roll out of equipment.