It's a beveled hexagon 30 millimeters between its parallel sides and four millimeters tall. This makes it fit standard Battletech mapsheets, among other things.

Other than that, what's there to say? The bottom is hollowed out to simplify removal from the build plate. If you want, you can glue a small coin down there for weight.

Print it out.

Add it to other print jobs.

Use your imagination. The possibilities are infinite with a truncated hexagonal prism!