The "beams" are around 24" long, I would have to measure them.
The frame connectors are installed the usual way, check out Jeff's frames here: http://hybridz.org/nuke/index.php?name=PNphpBB2&file=viewtopic&t=35320&highlight=frame+connector
The lower mount of my "beams" are mounted to this. Check pic from my site.