About this 3D model

I was wandering through the hardware store recently when I saw a "universal caulking cap". They also had something similar that was a dispenser tube that you could snap on. . Well, instead of dropping stupid amounts of money on the things, I ran home and coded this up! . You can generate either a closed cap, or a connector with a hole in the end for attaching to other designs. . UPDATE: I've included an stl for the universal cap, since that's probably what most people will want there's no sense re-generating it every time!