Re: KM Americana.
None of the large protectors I have fit the Jumbo anywhere close to "pretty damn good" and I have around 10 of them, including the ones that are included with KM vases. Larges are sized for size 30 bell vases with bottom flanges that are 6" in diameter. The Jumbo has a bottom flange that is 5.25" in diameter. This is slightly larger than the intended use of a small protector but since they do stretch and the Jumbo's flange is shallower than small bells, they can fit on there. IMO it's better to have a protector that is tightly on there vs one that can easily be pulled off.