Yes, this is a 3D model of a rectangle.I am writing a blog series about designing a low cost yet very capable homemade testing machine and using it to analyze the mechanical properties of 3D printed materials.This rectangle is actually a test specimen specifically designed for a 4 point bend loading on my machine. .You can follow along with the project at the link below, any feedback or fresh ideas will be greatly appreciated! What mechanical properties would you test  http://engineerdog.com/2015/03/24/introduction-to-3d-printing-materials-testing-series/