This is a great little bag, I've strapped it to my 1300GS with ROK straps using the grab handles and its rock solid. It does come with its own straps but they are those D ring type and not as quick to clip off. The bag itself is about 14/15 inches wide with a large flap that lifts to reveal a zip which opens just smaller than the flap itself so you can put large items in. I would say the zip opening is about 12 inches wide. I'm using this for a Naturehike Cloud Peak 2 tent, as well as other camping bits Stove, and other cookware. To give you a good idea of size you could get two of those tents in this. It also has some D ring attachments on top of it which I strap a Tarp to. It isn't described as waterproof but it is lined with a waterproof material and in recent downpours hasn't leaked. I've attached two pictures to this review, on one you can see I have a heat reflective sleep mat looks like its full but it isn't the tent will still go in there as well. I have now stopped using that mat as I've upgraded my sleep pad.