This is pretty cool.

[ozkat]

http://www.powerchutes.com/manometer.asp

[DaveK5]

I made a similar 4 tube unit to syncro the carbs on the old yam I'm workin on...best to use ATF as the fluid...mines approx 1.8m tall and mounted on the wall of the garage.
Fit a thicker filler tube connected via T pieces to 1/4"tube and 1/4" irrigation valves to equalize the fluid levels..shut em off and away you go.
Miles more accurate than gauges..got the carbs within an inch...unreal

Basically the same as mine, except they charged me $120 because it has mercury in it.

And the glass tubes all cracked within 6 months. Bitch of a thing