mtudo98,
I forgot about that one!! Yep, I was a sucker too!!
It gouged the balsa with the two little feet that pivot (kind of), and never did mark the center of my trailing edge. I use a ball point pen now with masking tape wrapped around it to make it the right circumference. Draw a line, flip wing over and draw another line to confirm center. Cheap, accurate, and easy. I did throw that one away.

Pilgrim