Fits 1/2 to full size violins and 12-15 violas. The “PSR PLUS” violin viola shoulder was created specifically for the beginning student with a slightly longer neck. The steeper slope over the collar bone will remind the student to hold their instrument up without drooping it over their chest. The PSR Plus is different than the PSR Original in that it provides additional thicker foam to grip the back of the shoulder for additional support and height to fill more space between the jaw and shoulder. The curve over the back of the shoulder will also create a more stationary feel. One “PSR Elastic Band” and one “PSR Magic Strip” are currently included. Try the “STRAIGHT” or “ANGLED” placements for your preferred comfort, made of resilient contoured ergonomically designed foam with great memory to bounce back to its original shape. Our PATENT NUMBER 7,262,352 design curve assists proper placement for your shoulder rest.