Refill Tip Adapter for 950 951 932 933 XL Cartridges - 4 PCS Tip Adapter for refilling 950/951 and 932/933 Cartridges Can be put in front of regular syringes for tool-free easy refill. Tip OD = 2.8 mm; Tip Length: 9 mm; Base ID = 4 mm; Base Length: 10 mm. Find the ink outlet hole (see picture), insert the tip all the way into the hole Inject ink and then release the syringe. Wait till the air fill up the syringe and pull syringe out. It can fill cartridges many times untill the printer prevents further usage, or you can install a permanent BCH950ARC4 chip (B00UNI03F6) and refill the cartridge forever.