Find compatible ink cartridges designed specifically for your HP Deskjet 3940 printer, ensuring reliable and high-quality printing. Our range of compatible 21 C9351AE Black Ink Cartridges and 22 C9352AE Tri-Colour Ink Cartridges are engineered to meet the exacting standards of your device, providing you with a cost-effective alternative to original equipment manufacturer (OEM) supplies.