Replacement sealed lead acid for APC Smart-UPS SRT SRT1000RMXLA SRT1000RMXLA-NC SRT1000RMXLI SRT1000RMXLI-NC SRT1000XLA SRT1000XLI SRT1500RMXLA SRT1500RMXLA-NC SRT1500RMXLI SRT1500RMXLI-NC SRT1500XLA SRT1500XLI APCRBC155 RBC155, 4 Cells 12V 9