Compatible Models: This print head is compatible with HP Photosmart B110a, B209a, B210a, B110b, B110c, and B110d printers. Durable ABS Shell: The print head's ABS shell is more wear-resistant and has been tested extensively to ensure performance and smooth printer operation. A small amount of residual ink may be present, which is normal. Easy Installation: The print head can be installed and used without any accessories or disassembly, preventing damage to the original machine. Be sure to turn off the power before installing the nozzle. High Performance: The print head chip identifies ink cartridges quickly, ensuring smooth ink ejection, printer protection, and clear, bright prints. Functionality Tested: Each set of accessories undergoes print head testing before leaving the factory to guarantee performance. Manual assembly and machine testing ensure high product performance.