woodshop
Addicted to ArboristSite
http://www.rip-saw.net/beamkit.html ...that will take you right to the guide beam page. They do sell just the beams themselves, they come in 5 ft sections, and thus 2 are usually plenty for most of what I do. The whole kit though, which includes the brackets etc to attach to a log (needed) will set you back buck seventy five plust $35 for shipping, and for that you get two sections and all the hardware needed to use on a log. Pricey... but you get what you pay for, these work and work well. I use them for my csm also.