This is a prototype design for an aquarium bubbler. It does not have a built in air connection spigot. Rather it has been designed to be glued or epoxied into a shallow disk shaped depression (18 millimeter diameter, 3.1 millimeter deep) in a structure that provides the compressed air source. For example you could design a bar or other geometric object into which you could insert one or more of these bubblers. I have also used the plastic fitting from an old air stone and epoxied it in place over the hole. Old air stones can be easily broken apart with a pair of pliers to release the plastic end piece.
The (89) bubbler holes in the spherical shell will be smaller after manufacture than they are drawn, being barely visible in the test prints I have received so far. As a result the bubbler appears to be similar to an air stone in operation. The holes may be carefully drilled out with micro-drills if desired but you'll need to be careful since it can change the behavior of the bubbler. (Too many large holes can result in just a few holes emitting bubbles, as I found after drilling out all holes with a drill bit that was too large.)
If you want to try this bubbler here are other issues to think about:
1) There will likely be some nylon powder remaining inside the bubbler that needs to be removed before use. I managed to do this in a pan of water, with a tooth pick to loosen up powder inside the shell, running water from a faucet for rinsing, and a lot of shaking the bubbler with water inside for further rinsing. This style of bubbler is much easier to clean since it has no long spigot tube for connection to an air hose, but what you get depends on how well the good folks at Shapeways manage to remove powder before shipping.
2) Not all holes will be of uniform size so some holes locations may emit more air than others. In general the bubble pattern is a function of holes sizes, total area of all hole sizes, and air pump pressure. If you drill out holes to enlarge them the bubble pattern may change.
3) I have no idea how long a bubbler like this will last. The holes may enlarge over time or seal up from loosened nylon powder.
4) The bubbler plastic will have some roughness and surface porosity which can provide a foothold for the growth of bacteria and algae, but that's not necessarily a bad thing. If this is a problem such nylon parts can be sterilized by soaking in a diluted alcohol solution and then thoroughly rinsed in water before use.
The safety of using 3D printed materials in aquariums with living creatures is debatable, so if you have doubts plan on using 3D printed parts in a decorative aquarium containing only plants, snails, and other robust creatures. This product is recommended for purchase using the regular white nylon plastic material since the coloring process might clog the holes - although color options are offered if you wish to experiment.
This is just a fun experimental design.