This kind of neck, with a mouthpiece big enough to put your lips in, not on. Not sure about the actual size of this mouthpiece opening, so it very well may fit the description. Picked flared in the poll tho because a flared opening to the mouthpiece is nice.
The reason I choose this kind of neck, is because it not only looks nice coming out of the opposite paert of the can as the joint where the vape is going to be sitting, and adds a symmetrical look to the piece, but it also allows you to look directly into the can to see the bubbling, to control draw speed, and the vapor density as well. It also looks really cool seeing the bubbles pop with little clouds of vapor billowing into the can. Especially if you have a light (phone flash or something) to shine into the side of the can.
A sidecar at least lets you see from one eye, and offers the option to have less height to the piece, but the necks coming from the top just don't make sense to me. Only on straight tubes that you don't use on a desk usually, but rather hold in your hands/lap at an angle. The way those are built, if they are tall enough, you can still see into the tube to see the density of your hit, sometimes. However with bubblers such as the one pictured and others with a main can section, having a neck that is curved, that comes from the top, forces you to basically look forward, and miss all the action inside the glass.
