Thermal Printhead for ZD421 300dpi Thermal Barcode Printer Print Head, 90days Replacement thermal printhead designed for use with ZD421 300dpi thermal barcode printers.This print head is engineered to deliver consistent performance for barcode printing applications.It supports clear and accurate thermal printing on label media.The unit is built to integrate with compatible printer models.Designed for straightforward installation and in standard printing environments. Compatibility Statement: This is a third-party replacement.Brand/model references serve only as compatibility indicators.