Sure thing. The switch is at the bottom and has a locking ring, the one with the bumps on it to be larger and easier to turn with a finger. The 'handle' part freely spins and is the button. Inside there is a short piece of vinyl tubing to isolate a screw from the negative of the battery. The switch housing is a turned brass cap that friction fits inside the main tube, a 7/8" OD ~13/16" ID tube.
On the other end is an atomizer borrowed from my Booster mod, that has a 15mm OD. It is surrounded by the barrels which are 2mm OD tubes. They are soldered/brazed to the inside of the 3 rings which are 13/16" OD, 3/4" ID and form the top cap of the mod. The barrels are snug on the atty, but you can press it through from the bottom, if you try pulling it through it pulls off the mouthpiece.
So with the atty in the barrels part, the OD is now 13/16". The tolerance is not quite right to let it slide into the mod, so the main tube is sanded some to allow the top cap to friction fit in the end. Between the battery and the atomizer is a brass disc that slides in to pick up the ground and an isolated positive post. The disc is from the top of the Gummy tank which was the best fit for the ID of the main tube. The positive post is slightly offset and isolated with silicone tubing to be slightly flexible, and the disc has a small hole drilled in the side with a spring in it to make sure the negative has good contact.
I hope this makes it somewhat clear.
