This Jet Tec M21 is a remanufactured HP no.21 (C9351A) Black Ink Cartridge for use with :

For use with :
HP Deskjet 3920
HP Deskjet 3940
HP Deskjet D1360
HP Deskjet D1460
HP Deskjet D1470
HP Deskjet D1560
HP Deskjet D2330
HP Deskjet D2360
HP Deskjet D2430
HP Deskjet D2460
HP Deskjet F370
HP Deskjet F375
HP Deskjet F380
HP Deskjet F2180
HP Deskjet F2187
HP Deskjet F2280
HP Deskjet F4140
HP Deskjet F4172
HP Deskjet F4180
HP Deskjet F4190

HPFax 3180

HP Officejet 4315
HP Officejet 4355
HP Officejet J3680
HP Officejet J5520

HP PSC (printer/copier/scanner) HP PSC 1402
HP PSC 1410
HP PSC 1415
HP PSC 1417

Jet Tec supply both compatible inkjet cartridges and remanufactured inkjet cartridges as well as refill kits for a wide variety of inkjet printers. Their cartridges have won many awards including the Queen's Award for Enterprise:Innovation 2004 for their patented Extralife technology which is exclusive to Jet Tec.