HP Indigo ElectroInk Lot Of 2 Black Q4137B For Indigo WS6000 W7200 7000 series and 8000. Quantity: Lot of 2 ElectroInk Calibration Cartridges. This HP Indigo ElectroInk Black Calibration Cartridge.Is a high-quality ink designed for use with the WS6000, W7200, 7000 series and 8000 printers. It offers excellent color accuracy and saturation, making it ideal for printing a wide range of professional documents, including marketing materials, brochures, and other graphic designs. COMES AS SEEN IN LISTING PHOTOS. Use of them does not imply any affiliation with or endorsement by them.