Replace the ink in your hp deskjet or envy printer with the hp 305 6zd17ae301 black tri colour ink cartridges.ideal for home or office use, this 2 cartridge pack will give you up to 120 black ink pages and 100 tri colour pages.hp instant ink save up to 70% on ink with hp's instant ink service'. '.strtoupper('w')hen your printer is running low, it automatically orders more ink cartridges, so you don't have to order them yourself'. '.strtoupper('t')he service works on how many pages you print, not how much ink you use'. '.strtoupper('y')ou can choose from a range of monthly page plans, and unused pages roll over to the next month'. '.strtoupper('t')he price includes ink, shipping and cartridge recycling.compatible printers hp deskjet 2710 hp deskjet 2720 hp deskjet 2300 hp deskjet plus 4100 hp envy 6000 hp envy pro 6400