Single wound string.  Please, make sure the string you are ordering is a wound or plain.
Under string name give us the note, and the string number, counting from the bass. 
Choose Double or Single wound,
Then choose the string style from the drop down menu.
To determine what string style you have, enlarge the pictures below by clicking on them. If your string style is not listed, singles are not available.

String numbers 1-13 are wound, the rest are plain.
Watch our helpful video here for stringing tips and tricks!