According to Partzilla, they are the same part numbers.
+1 They are the same size.
Seller probably confused Tourer with Interstate
That's what I figured, but the listing also mentions them not fitting the IS.
I didn't want to link to the listing, but here's a verbatim copy/paste from the listing:
THESE DO NOT FIT THE INTERSTATE DUE TO DIFFERENT GAUGES IN THE FAIRING
THESE DO NOT FIT THE "TOURER" MODEL--I MIGHT HAVE THAT SIZE AVAIL BUT WILL NEED YOUR MEASUREMENTS
THESE FIT THE CRUISER MODEL ONLY
I have a Tourer, but am in the process of installing a fairing so I can't check, but I don't recall the gauges being that close to the windscreen, and his warning makes it sound like the gauge itself is different. Weird.