1. Click on the edit icon from the configuration screen
2. Check Bootstrap Enabled
3. Click on Add new record…
4. or modify an existing item by clicking the edit icon
5. in the Grid System Entry Screen
6. Click in the ID field and specify your entry
7. Set the display name
8. Specify the Numerator and Denominator
9. Specify classes
10. Click on On By Default
11. Click on Update
12. Click on Save
