I picked up this Ortlieb bag from eBay, and I have no idea,







how to attach it to a bicycle, it appears to me, to be a rear pannier? Maybe it needs a mate, on the other side .?I want to use it, as a single . This looks like an old one I can tell by the insignia. How on earth does it attach and to what I do not know. it is a mystery to me. kindly advise if you've ever seen one like this thank you so much. The last picture is it in an upside down position, the first one is right side up