I found it when I was looking for a practical medicine box (personally Fujifilm Ale), and the inside dimension seemed just fine for the size of the medicine bottle. I bought S-121 two in the form of a medicine for a tube or paper box package. The size is perfect. It was the best match next to the first aid kit with exquisite size that medicine bottle that you normally use in the home (too big is impossible) fits well exactly.
Because it was possible to connect with a cassette with a different size, we use S-112 type of S-112 of this manufacturer in combination with S-121. We put small items on S - 112, large ones and large quantity on S - 121. Since it can be connected to various shapes, places where you can choose any combination are useful.