I'm with bkharmon in regards to the Makita joiners. I use them with an 8020 1012 extrusion to insure straightness. That being said, I ended up springing for the 491501 FS 3000 118" guide rail because I cut up to 10' lenghts are a regular basis. So, I own every size and more than one of some.The only one I don't own is the 5000mm.