If it is to be coupled, one would ansich, somewhere can specify which side you would like the opening. I have (for now to test) ordered just one and promptly was the opening on the wrong side, at least in the test bed ... my purpose is in fact, that I would like to have for the next vacations in apartments for hygienic reasons my own bedding case and the like around it and also please with hood that lies over the "foreign" pillow. A sleeping bag or business as usual scenario: a Brought duvet cover, in whom I am pure hatched, to me somehow not enough.
Now comes my Reason for return: I should have more confidence in the temperature data: it is too warm for me. Earlier it was like cheating because, in any case holds my old (Down-filled) sleeping bag (at least from Globetrotter) not nearly as warm as indicated. This one already much more, for indoors, even in unheated bedroom in the approximately 16 °, it is me just too much. Although you could tell a certain breathability, so I'm not really come Doll sweat and one can also partially let air from the side, but I would rather be resorted again to the ceiling ...
But if I plan to take my self-vacation with a tent, I would keep the sleeping bag with safety!