Help identifying this component?

photo_2019-06-12_01-07-23
Hi,

I was trying out this tutorial from here: http://www.iaacblog.com/programs/assignment-4-kangaroo-mesh-relaxation/
At the first part to define the starting geometry, I saw this component but I could not identify it, could someone help me out with this?

Thank you very much !!

Thank you !