How to Properly Fit and Use a Bon Musica Shoulder Rest: It is not necessary to perform the adjustments described below because your shoulder rest is ready-to-use and adapted in its basic adjustments to an anatomic average setting. However, you are enabled to bring your Bonmusica  violin or viola shoulder rest into a configuration optimized to your physical conditions, permitting relaxed playing by relieving your head in the neck region, without any pressure marks on your neck and chin. Additional Instructions can be found at the Manufacturers website: Feel Free to visit: http://www.bonmusica.com/texte/gebanl.html