You should determine the name based on the specifications.

Because your name is not unique. Specifications are unique. Your selection criteria is name, and excel will select the first value that meets the criteria, so that's it.

I don’t know what your situation is. Based on this information, index match cannot be used to solve it.

My understanding is that it is better to use cascading menus. Select a name and manually pull down to select a specification.

You simply lack a parameter to determine the specifications. Under what circumstances is 1100ml? How to determine whether to choose 2250ml...