The Walgreen's el cheapo boar bristle brush fits in it perfectly, so I thought that the brush was some sort of standard size. Then I was at Leavitt & Pierce in Harvard square, & all the badger brushes they have are too small for the stand. Then my GF bought me a gift; a badger brush from Art of Shaving in Chicago. Once again, it's smaller than the boar brush & too small for the stand.

What's going on with that? Do I need a size XXL badger brush or something so that it fits in that stand? Which brand of brush was that stand intended to fit?