The prototype Pencil Mics were designed using a 1" Aluminium tube to match the size of the capsule, and the length 14" to match the size of the preamp board.
I designed and printed the 3D parts coupling the capsule to the tube, and the other end coupling the XLR mic connector. I then went on to spray the tubes and laser cut the logo. The preamp board amplifies the signal from the capsule and fits nicely in the tube . Overall they have a nice warm sound.
I 'm considering redesigning the capsule coupling and opening up the back of the capsule and adding vents, as this changes the tonality of the sound. So there is some scope for improvement.