To select an enzyme check it in the list. Notice that the enzyme appears in the Selected enzymes area of the dialog.
You can also use the Select All button to select all the enzymes available, the Select None button to deselect all the enzymes.
To select all enzymes with recognition sequence length shorter than the specified value click the Select by length button and input the minimum length in the dialog appeared.
To invert selection click the Invert selection button.
As soon as enzymes are selected you can click the OK button to search for corresponding restriction sites in the sequence.