What a bummer, it appears that Xcaliber Shafts - one of my favorite product lines in recent years - may be coming to an end. Unfortunately, Robin Arthur (the owner) has been having some health problems and has stopped making shafts as a result. Golfworks said that the shafts won't be produced any longer, and once they sell through the rest of their inventory they are all gone and may never be made again. Hopefully this is just something temporary and we'll see him making shafts again sometime, but for now - get them before they're gone!
https://www.golfworks.com/search.asp?start=10&ss=xcaliber