Custom, by me. Was a pretty quick prototype and doesn't really work all too well with the big saddlebag. Made a new one right after that gig but no pics yet.
If you want something to hold up a big carradice, the bagman expedition with the new(ish) struts works really well. Used mine loads now and it's really great, even when overloaded (naughty).
Overnighter setup from a couple of weeks ago testing out the bigger Super C saddlebag.