Model 14571 is an analog micron gauge with dual power source, will run off of 2 D batteries or can be plugged into any 110V outlet. These arent the cheapest gauge but it is reliable as all get out.
I have only used the Thermal model14571 and found that it works very well. We have had a few problems in the last year with the thermistors going bad for some reason though. After reading this thread I am really intrigued with the blu vac! Might have to try one.