15mm Building Unit with Slit Windows

This is the only product I currently offer with a cute story behind it.  In my senior year of college, I was instructed to design a children's toy with multiple components, then devise the most efficient production method that was still flexible enough to produce different quantities of each component, depending on the market needs (remember, salespeople run companies, not engineers such as myself).  Even though I still aced that particular class, I wish I had this idea back then.  Here's the story of  how I came up with it: one day, while looking at hexagonal rotor hubs (I work as an inspector at a company that makes parts for jet engines), I started stacking the parts that I had finished into a rather artistic pile, and thought to myself "this would make a neat-looking castle, perhaps I should make some hollow plastic hexagons the same size and stack them."  I wound up integrating the idea into chuyinka culture, giving them this sort of advanced pre-fabricated building technology that allows them to stack as many of these units as they want together, and knock out walls, ceilings, and floors in between them to create huge interior spaces.  The units I currently offer are rather basic, just because I wanted to save my fleeting idea to a hard drive before I developed it further.