CISS for HP Deskjet-3520-3522-3521
Step one
Preparing the ROBUST V.4 tanks NEW!
**The Small Plugs (Tanks Plugs) need to be left open at all times after you install the system
STEP TWO
Please Note, The way to install the CISS is the same, just the CISS' shape is different.
Warning :
Never rise the external tank higher than your printer (even temporarily)!