This is the shoulder rest that I recommend for violin sizes 1/8, 1/4 and 1/2.
These now come in size 3/4-fullsize as well. Up till now I have recommended Kun shoulder-rests for size 3/4 and full violins but now the viva flex is another good option.
The brown and black colours are very similar (almost indistinguishable to me!)
The legs can be moved in or out so it can be adjusted to fit the width of your violin.