Gossen Luna Pro Light Meter - Battery Testing

I have an old Gossen Luna Pro light meter. The operation seems ok but when I am a little confused on the battery test. The instruction booklet says that when pushing on the ridge slide on the back of the unit, the indicator needle should point to the red check mark ot 12. Well , there is no red check mark at 12! There is a small red rectangle at about EV 8 if using the upper scale or 17 using the lower scale. Is this small red rectangle what they are talking about?

Thanks!!

Bruce

yes

I had (still have, actually) a Luna Six, predecessor to the Pro. Just an fyi, the needle never did land exactly where it should have been, just close, but consistent.