The tool is even unnecessary. I successfully used a length of thin flexible tubing that I filled with water and hung from a ladder to create a manometer. The hardest part was filling the tube with water and getting all of the bubbles out...
I can't say I noticed anything different after I balanced the throttle bodies, but I will try to notice next time.
When it comes to havoc, no one wreaks like me! - Dr. Heinz Doofenshmirtz
I will never be good and that's not bad. - Ban-Anon