No label defined (Q68367)

My Grandfather recently died and when we were sorting through his old air force stuff I found this thing. It is solid black very dull metal with precision cut geometric shapes. The number at the top was etched in by someone later because it is not as well cut into the metal as the shapes. It weighs about five pounds. When he showed it to me when I was younger he always called it the "Alien data disk" (hence the name), but told my mom when he thought I wasn't listening that it was an "interface disk". Then at some point he said he threw it away, but luckily I found it along with his other stuff. Anyway it is kind of cool looking so I used it as my first sketchup project. The dimensions are pretty close if you scale it down to 0.01. The rounded edge on this thing is scratched up pretty bad, but I couldn't add the effect in sketchup. The shapes in the disk are visually accurate to the original but not measured perfectly; not that it matters much to anyone else.