Which twin stroller do you have? Is it a side-by-side or a long one? I imagine it would fit on a long one, not so sure about a side-by-side.
Hi, I have a side by side stroller. It is a Steelcraft Twin duo. Just like having two strollers joined togrther. I've had a look at the frame on it (square tubing). Looks like it may fit behind one of the seats attached to the middle bar. If I can get away with this it should be ok.
Might take the stroller to one of the babyshops and see if they can try one on the strooler if they have any just to be safe.