Yep, I bought mine over ten years ago. An SQM-L - I don't think they had many options in those days. Really just to get a reading, particularly comparing darkish locations when you wanted some backup to what your eyeballs thought.
Point it to the bit of sky that matters to you. It will certainly tell you when the Milky way is at the zenith - a noticeably lower reading.
I recall some discussion years ago on IIS about keeping a well-charged battery in it.
Just looked - Oh, it was my thread
Sky Quality Meter (SQM) readings
I'll bring mine when I get an invite to visit.......
