Digital pH monitor?
 

Anyone used one of these before, I just did a random ebay search and came up with a bunch of cheap black and yellow monitors, due to the low price I'm kind of curious about the accuracy.

My dad has one of those and he lets me use it for my aquarium sometimes. i don't know if it is the same brand cause it was not cheap. They work well and even tell you the temp :-) the only thing is that you have to adjust the machine to read the ph properly, once in a while.