Cortex came in longer sheets than standard wrap so they could wrap an 18 or 20" drum with a single piece and just one seam.I don't see anything hinky here.

Thanks for all the input guys.The listing said the drum is 18.5" tall and 20.5 across it does not matter they will not ship the drum anyway...Mikey777

Very interesting. The hoops add a half inch to the height of a drum (I can't remember what they do to the width), so unless they're measuring poorly and also rounding up, that's definitely an 20x18, even if the perspective doesn't show it in the pictures.Also note the number of vertical bands on the drum. Below is a photo of this drum and one of an 18x16 from eBay. From lug tip to lug tip, the Goodwill drum touches 10 butcher block bands. On the 18x16 the lugs only have 8 lugs between them, at most.