R4 Series Four Post Open Frame Racks are designed for heavier, deeper, digital components. Made by Middle Atlantic Products of Fairfield, New Jersey, the racks promote effective thermal management, cable, and space requirements. The Open Frame Four Post Rack with Cage Nut Rackrail accommodates servers and other equipment requiring cage nut mounting hardware. The steel rack supports 1,000 pounds of equipment. The Open Frame Four Post Rack with 12-24 Threaded Rackrail supports networking, telephone, and voicemail equipment, as well as routers and switches. The aluminum rack supports 2,500 pounds. Patented base angles can be installed inside or outside the enclosures for additional stability.