General Device RL-CC3084-99-0059 26-Inch Rackmount Mounting Rails. Can fit on any 4-Post Rack mounting system with a 26-Inch depth. These rails can extend up to 21-Inches, and each can support up to 80LBs for a total supported weight of up to 160LBs! These rail-kits come new in orginal GD packaging with installation hardware, and mounting instructions! These rails come with the C-300-S-4XX-RC-3S 3-Hole mounting brackets. These rails are perfect for 1-U applications, and they can also be used for larger applications!