There are several models in this series. The 9040 is the standard model, the 9041 is luminescent, and the 9045 has a thermometer.
My favorite is the 9040. Black in color so it’s easy to read in bright sunlight. I like to wear my compass on my lanyard all day, so I prefer it to be small. The compass on my lanyard (AirCore PRO Ursalite cord) weighs 0.5 oz.
My only gripe is that it’s just a teeny bit too small, and I’d prefer a slightly larger size if it could dial in two degree accuracy (it’s five degree as it is, which is fine for most nav anyways).
It lays flat on my chest and under my shirt, out of the way, with no sharp edges. This is a big bonus for me.