arcgis desktop - Creating Drop Down List Variable with ModelBuilder?

I am building a model and am trying to create a variable (that will be turned into a parameter and then added as a field) that is a drop down list where only specific values can be chosen.

Any help in how to do this. I have:

1. right clicked the white space in ModelBuilder


2. clicked on create variable


3. selected string


4. right clicked on the oval and chose 'list of values'


5. Entered my list items

This doesn't seem to act as a drop down when running the model. Am I doing something wrong? These are text values I'd like in the drop down.

Answer

Often a particular tool that will be accepting this variable may have the option of a value list filter for the parameter.