Any time someone lists wheel size as some number in inches, you can expect it to be a total mess.No idea, and how those can both be 16" is beyond me.
26" is a particularly remarkable case. Usually people are referring to 559, but there are at least five different BSDs that have been referred to as 26 inches over the years.
I really wish everything was advertised and sold according to BSD. A 2.1" 26er tire should just be 559-53. A "700x25c" tire should be 622-25. And so on. Sometimes they do label things like that, and it's a 15th competing standard that I can believe in.