Partsmart RS5-0230-000 is a replacement gear for the fusing roller drive in HP LaserJet 4 and 4M printers. It transfers drive within the printer’s fusing mechanism, making it a service part for that assembly.
The gear has 34 teeth. Its part number and stated fit for LaserJet 4 and 4M identify it for those printer models. This is a replacement part, listed against the corresponding OEM reference; it is not presented as an original HP component.