Feature:1. Easy Installation: This print head kit includes only one print head, no other accessories or extra tools are needed, just press the print head to complete the installation, saving your time.2. Material: The shell is made of high quality ABS, wear resistant and has been tested many times to ensure the performance of the print head and keep your printer running smoothly.3. High Performance: Upgrade 950 print head chip, identify ink cartridges faster, print head ink jets smoothly, protect the printer, print clearly and colorfully.4. Applicability: Compatible with for hp office Jet 8100 8600 8610 8620 8650 251DW 251.5. Note: Be careful when installing the nozzle, be sure to turn off the power before replacing it.Specification:Item Type: Print HeadProduct Material: ABSApplicable: for HP OfficeJet Pro 8100 8600 8610 8620 8650 251DW 251.Package List:1 x Print HeadNote:Incompatibility Solution: Reset the printer, follow the steps below to reset the printing device. Turn on the printer (if it is not already on). Wait until the printer has completely stopped before proceeding. After turning on the printer, disconnect the power cord from the back of the printer. Unplug the power cord from the wall outlet. Wait at least 60 seconds. Reinsert the power cord into the wall outlet. NOTE: for HP recommends connecting the printer's power cord directly to a wall outlet. Reconnect the power cord to the back of the printer. Turn on the printer (if it is not already automatically turned on). It may take a while for the printer to warm up. The printer lights may flash and the carriage may move. Wait until the printer has warmed up and stopped completely before proceeding. If the above methods cannot solve the compatibility problem, you need to replace the original ink cartridge and ink.