This thing includes two different styles of pins, one being rounded and the other being angled.
A geoboard is a mathematical manipulative used to explore basic concepts in plane geometry such as perimeter, area and the characteristics of triangles and other polygons. It consists of a physical board with a certain number of pegs, around which are wrapped rubber bands. (Wikipedia)
Being one of my favorite manipulative learning objects when I was younger, I had to submit it.