Before I was an engineer, I was a musician. So I was elated when someone asked me to design for them a set of instrument stands for various brass and woodwind instruments. These stands have interchangeable parts between sizes, and the legs store inside the cone. It uses a secure and easy to use locking mechanism. It’s really a great design. From this view, you can’t see the internals, which are part of what makes it such a nice design, but this is one of my favorites.