ALTERNATIVE TO OEM RAIL KIT: Provides a sturdy replacement for Lenovo/IBM System x3250 x3550 and x3650 M5 rail kits fitting standard 19' EIA-310 racks VERSATILE RACK COMPATIBILITY: Works with both 2 Post and 4 Post racks with adjustable mounting depth between 3'-30' (76.2 - 762 mm) supporting square round and threaded hole racks HIGH-QUALITY DRY SLIDE RAILS: Durable dry slide mechanism for long-lasting performance ideal for enterprise deployments and data center environments 2-POST CENTER MOUNTING: Center mounts in 2 Post racks with 3' - 6' uprights making it adaptable to various rack configurations SUPPORTS MULTIPLE UPRIGHT SHAPES: Compatible with L C and ? rack upright shapes making it a universal option for data center installations