What device is Blindguru using in this video to measure nutrients

[fuggles]

http://www.youtube.com/watch?v=3UdSLp3CCfg

from 3.40

he says look at the numbers from 1 to 32

anyway, does anyone know much about it ?

[Dimond]

Brix Meter:
Brix Meters are used when you want to see if a new nutrient or additive is really working for you in 1 weeks time instead of having to go through the entire cycle. You test the sugar content in the plant before you use the new nutrient and then you can test again in a week and know if it is helping or hurting your plants.