Tripp Lite BP24V15RT2U 24VDC UPS External Battery Pack for Select Tripp Lite UPS 2URM Offers extended-run UPS operation when used in conjunction with compatible Tripp Lite UPS systems Supports stacking or rackmount installation using only 2 rack spaces (2U). Minimum required rack depth (inches): 13.5 Includes heavy gauge cabling with high current DC connectors for simple installation 2 year warranty Note, limit of one BP24V15RT2U per UPS