It is suitable for both 1/4 violins and 1/8 violins. ADJUSTABLE: Fully adjustable for both height and angle, the shoulder rest is suitable for 1/4 violins and is adjustable to 1/8 size violins. To attach the shoulder rest to your violin, simply loosen the built-in screws, adjust the height and angle, and tighten them to adjust your violin onto the.