There are six regular convex polytopes
in 4D, which are analogous to the
five Platonic solids in 3D. This is the third, the hypercube or tesseract, in the classic projection into 3-space, showing its 8 cubic faces in a nice straightforward visualization.
A different projection is here
5.002 w x
5.002 d x
1.969 w x
1.969 d x