This is a very simple representation of a Qubit -- a Quantum Bit. Yes, it looks like a rotating bit inside the letter "Q", but it is really a crude representation of a qubit inside a quantum computer, which is essentially valued at 0, 1, or an indeterminate value potentially entangled with other qubits. Since this is just one qubit, there isn't any entanglement and the indeterminate value is signified by either having the bit rotated to any position between the 0 and 1 sides or, much more entertaining, by the central portion spinning. Although this prints assembled without supports, the center will spin quite freely when you blow on it.

The top of the Qubit has a cavity that can accept a 25-27mm diameter keychain loop, or cord/fishing line could be run through it to treat it as a pendant. The Qubit itself is 36x36x5.5mm.

This was designed to be a 3D-printed give-away for our group's research exhibit at SC18, and several hundred were given away there. Our group, Aggregate.Org, is based in the Electrical and Computer Engineering Department of the University of Kentucky, and that's why the raised lettering is there giving URLs. The "plain" versions are without the URLs. The number at the end of the file specifies the rotation pivot tolerance; 1000 is good for quick, coarse, prints and 500 works better with extrusion heights of 0.2mm or less.