BP72V18-2US rack / tower external battery pack offers extended battery runtime when used in conjunction with compatible 72V Tripp Lite Rack and Tower UPS systems. Supports 2U installation in 19 inch 4 post racks with included accessories. Optional 2POSTRMKITWM enables 2 post rackmount installation. Optional 2-9USTAND accessory enables tower placement. Supports the connection of multiple BP72V18-2US external battery packs with built-in daisychain connector. Includes heavy gauge cabling with high current DC connector for simple installation in rackmount and tower configurations. Compatible with these UPS Systems - SMART3000RMOD2U, SU3000RTXL2U, SU3000RTXL3U, SU3000RTXL3UHV, SU3000RTXLCD2U, SU3000RTXLCD3U, SU3000RTXR3U, SU3000RTXR3UHW, SU3000XL, SU3000XLCD, SUINT3000RTXL2U, SUINT3000RTXL3U and other Tripp Lite UPS systems that specify the use of this battery pack.