I have an after market head light and number plate and the bag fit perfectly. I really like the fact that I can care my camera in the bag and get instance access to it with out having to take off my pack. Really well build. Extremely happy with the bag.
I bought this for my crf250x. lots of buckles and straps giving a good secure tie down. Big enough to put my car keys, wallet, cell phone and a water bottle in with a little bit of room to spare. Construction quality seems good but since I've only had it a couple of weeks I can't say how well it'll hold up but so far so good. It's kind of goofy looking on my bike but not as goofy as a fanny pack or as cumbersome as a backpack.