AH, looks like with original setup, can only be used in pairs, they velcro to each other. So to use that one bag, would need to install clips. If available at a fair price, probably an Ortlieb rail, only attach it better with stainless steel bolts and nylock stopnuts or double nuts to torque against each other, I think I had read that original rails were installed with screws into plastic backing (no nuts) which would fail.