Swivel chair stilts

These are some spacers which can be placed in between a swivel chair base and the wheels to raise the swivel chair about 2cm higher than it originally was.
I designed this little piece because we ([HackerspaceSG](https://www.hackerspace.sg)) recently got a chair in which the middle cylinder had sunken through the base and started hitting the ground, destabilizing the chair and damaging the carpet.
The sources are kept up to date in Github: https://github.com/hyperair/chair-wheel-adapter