Yeah, it's the Motofizz, size large. It's meant to be mounted sideways but with both side extension panels opened, it's way too wide. It fastens nicely like that but of course only if you're riding one up. One of the smaller sizes would be better mounted sideways, the way it was intended. It does have a lot of straps and tie-down points. I like that the inside is just one big compartment. I pack some long gear so it's good that there are no dividers in there.
As to what I pack in there - Oh man, it's a bunch of stuff and I don't know if I can remember it all but ...
tent, sleeping bag, air mattress, kermit chair, footstool, 12' noah's tarp, pillow, LED lantern, folding table, littlejohn (to avoid that cold trip to the outhouse at 4am), fire extinguisher, sometimes I also pack a thermarest for extra bed cushion ...
I know there's more stuff but I can't think of it right now. There's always some extra room at the rear for a small bag of charcoal, a folded cooler and other stuff I pick up along the way. There's a cinch strap to pull it all up tight when I'm done. It's a great bag and it's very rugged. I'm tough on my gear and I'm sure it'll last a while. The thing opens wide from all angles so it's easy to get stuff out from any direction. I recommend it.
Over the years I've come to appreciate having everything inside one bag. I used to lash down separate pieces of gear but it's very nice just to unsnap four buckles and carry the whole thing off with the pole bag lashed to it. No bungees, no ropes, no hooks. The few times I (reluctantly) have to hotel it, it makes it very easy to carry in all my camping gear with one trip.
Now those extra panniers, that's a different story. I only put those on if I'm going to be cooking, but that's most of the time. I usually just unload them and leave them on at the campsite but if I'm concerned about security it's not a big deal to pop off the seat and carry them in too. I must admit that usually I just take off the big bag and put the cover over the bike and don't worry about the extra panniers all that much. If I'm parked in front of a motel I usually just chance it.