BP48V48RT4U - 4u rack/tower external battery pack offers extended battery runtime when used in conjunction with expandable 48V Tripp Lite rackmount and tower UPS systems. 4u reduced-depth configuration with included 2 post mounting accessories is ideal for use with Tripp Lite Compact Rackmount models SMART2200CRMXL and SMART3000CRMXL. Includes heavy gauge cabling with high current DC connector for safe, simple installation. Included daisychain connector enables the connection of additional compatible 48V external battery packs to the host UPS. Included mounting accessories support 4U balanced 2 point center-mounting rackmount installation in 2 post racks. Options for 4 post mounting and upright tower installation available.Compatible with these UPS Systems - SMART2200CRMXL, SMART3000CRMXL, and other Tripp Lite UPS systems that specify the use of this battery pack. (Note: BP48V48RT4U, SMART2200CRMXL and SMART3000CRMXL include hardware for 2-post rackmount installation; most other rackmount UPS systems and battery packs include hardware for 4-post rackmount installation.)