This design can hold toothbrush and toothpaste. As I have seen, there are two more regular sizes in toothpaste caps. The bigger one stands in the flat area and the ones with the small cap, they go through the hole and rest on the "shoulder" of the tube.

all the pieces snap in place, super glue is optional but recommended.

The suction cups are 35mm and you can find them in ali Express ( https://es.aliexpress.com/item/4001338849355.html?spm=a2g0o.productlist.0.0.5e732a30CsYzT1&algo_pvid=96288e6b-cc8d-4de8-bbcc-b0bdede90ac1&algo_exp_id=96288e6b-cc8d-4de8-bbcc-b0bdede90ac1-0&pdp_ext_f=%7B%22sku_id%22%3A%2210000015733833009%22%7D )

Hope you like it and find it practical for you.