This is a genuine HP 40W AC power adapter (charger). Key identifying part numbers include HP Part No. 580402-003, Replace With HP Spare No. 584540-001, Model Name HSTNN-DA18, and Mfr. Name ADP-40VH B (by Delta Electronics). Key Specifications Feature Detail Source Input 100-240V ~ 1.1A, 50-60Hz Output 19.5V ⎓ 2.05A Power Output 40W Connector Size 4.0mm x 1.7mm (often a black or yellow "bullet" tip) This power supply is compatible with various HP and Compaq products, particularly models in the HP Mini notebook PC lines.
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