Weems & Plath Marine Navigation Matte Nickel Divider (7-Inch)

I bought this item for my U.S.C.G. 6 pack license course. I was being cost conscious when I purchased it and that was a mistake I could have bought a much nicer divider for just a little more money. This one is hard to adjust and tends to spring back a little after you adjust it. I passed the course but I was truly struggling with this thing on all the charting exercises and testing.