The best way to tell if you need a ball end or a loop end string is to look at your violin's tailpiece. The lower three strings are generally only available with ball end. If the violin's fine tuners (string adjusters) are all the same, you will probably require a ball end E string. This set-up (four ball end strings) is common for most violins, especially small size violins. If the E string attaches differently to the other strings or is the only string with a fine tuner, you may need a loop end E string. A loop end fine tuner, also known as 'English' or 'Hill' model, has a hook which attaches to the string's loop end under tension. A ball end fine tuner has two prongs which hold the ball in place.