Unistrut http://www.unistrut.us/
Superstrut http://www.tnb.com/pub/en/node/192
http://www.graybar.com/document/tnb/superstrut-quick-reference-guide.pdf
http://tnblnx3.tnb.com/emAlbum/albums//ss_us/ss_series1000.pdf
