The ideal tool you need for refilling deskjet printer using  HP 51640 51645 6615 240 45 15 HP51645 HP6615 HP51640 HP240 HP45 HP15.
high quality ABS material
small size
simple operation with detailed manual instruction with pictures
Easy to follow instructions. Refill tool can be saved for the future and you will just buy ink from now on.
EASY TO REFILL- Just peel the sticker on top of the cartridge, you will find a hole for refilling the cartridge, take ink in the respective syringe and inject as much ink as the sponge inside the cartridge can absorb, then paste the sticker back. Watch demo video on YouTube channel.
Operation steps:

Insert Inkjet Cartridge

Insert the nozzle part of the cartridge into the refill clip and push the top of the cartridge all the way in until you hear it “clicking” into place.

After turning the refill clip upside down, remove the black film at the bottom of the cartridge, in front of the nozzle.

Push the metal ball inside, opening an ink injection inlet.

 

Refilling Ink

Connect the ink container/syringe to the ink injection inlet.

While keeping the refill clip upside down, inject appropriate volume of ink by squeezing and releasing the ink container/syringe slowly.

Warning: The ink volume specified above is for a complete empty cartridge.

Completely close the injection inlet after ink injection.

 

Stabilize Internal Pressure

Connect the syringe to the rubber hole of the refill clip, and slowly suck our internal air until 1ml of ink is filled in the syringe.

(Depending on the cartridge condition, 6-7ml air will be sucked out before ink comes out)

Remove the cartridge from the refill clip and clean the excessive ink around the nozzle, dabbing the nozzle part on soft tissue.

Install the cartridge into the printer, and run “head cleaning” process before use.

For use in the cartridges:

HP51640(HP40)

HP51645(HP45)

HP-C6615(HP15)

 

Ink Volume Reference:

51640a/c/m/y 42ml

C6615D 25ml

C6615N 14ml