I really love this thing, it has a certain 80's car gadget charm with the old skool LEDs.
We choose this one because it was one of very few available in the US and many that are available are number read outs that can be hard to read at a glance. The LEDs and colors make it easy to know where you stand. This particular one can be used with any dual battery system. Many nicer monitors are also controllers and can only be used with the full system that they were intended for.