Patron BUSH-HP-P2035-PN is a set of rubber-roller shaft bushings for HP LaserJet P2035 and P2055 printer cartridges. These parts support the roller shaft inside the cartridge and let it turn during printing.
The bushings help keep the roller shaft in its place as it rotates. The listing also notes that, in some cartridges, a bushing carries current between the transfer contact and the shaft. This set is intended for the listed HP printer series and is identified by the exact Patron MPN above.