The HP 902990-001 is a mains adapter for powering a laptop. It converts household AC into DC for a connected computer, and can serve as a replacement when the laptop requires this exact part and matching connector.
It supplies 19.5 V DC at 3.3 A, with a maximum output of 65 W. The listed AC input is 100–240 V at 50–60 Hz, so check that the laptop’s power requirements match these ratings.
The output connector is round and straight, with a centre pin. Its outer diameter is 7.4 mm and inner diameter 5.0 mm. The adapter is listed as an HP product in black. These connector details help identify the specific variant when checking a replacement.
Use the adapter for a laptop only when its required input and connection correspond to the stated specifications.