We decided it might be bad to breathe the exhaust fumes from our 40 W hobby laser so a few members decided to do everyone a favor and rig up this elaborate duct system to make things a little safer for everyone. Now instead of filling the shop with various gasses and particles it is blown out through this duct work and outside through the giant exhaust fan upstairs. Safety first!
Just make sure you add the appropriate laser-related signs: http://milwaukeemakerspace.org/2012/04/signs-of-the-makerspace/