These are replacement batteries for PS-1250-F2 HR1221W RT1250-F2 NP4-12-F2 HR5.8-12 and UB1250-F2 (D5777). We supply only brand new factory fresh high quality batteries. We guarantee the best price and 100% compatibility with your Compaq AF423A model. You must use the existing cables and hardware to connect your replacement ups batteries. The replacement sla batteries also include a minimum of one year warranty. Compaq AF423A UPS Batteries (Replacement) - 12 Volts 5.5 AH F2 terminal Our brand new replacement battery set for the Compaq AF423A Uninterruptible Power Supply (UPS) unit includes 10 SigmasTek SP12-5.5HR batteries (12 Volts 5.5 AH). Please note that you need to use all existing cables and hardware from your original configuration in order to connect the new UPS batteries. The replacement Compaq AF423A UPS batteries have the following characteristics: High Rate Discharge Design; Valve Regulated Spill Proof Construction; Low Self-discharge; High Vibration Resistance; U.L. Recognized and CE Certified; Superior Performance; Brand New, Factory Fresh; 1 Year Warranty