Batch of 3 Resonans Shoulder rests for violin or violas

I got these with a batch of miscellaneous musical equipment parts from a music shop that was closing and I honestly don't know a thing about them. They have some signs of age, mostly from sitting in the shop unsold it seems to me, as what I was buying from the shop was old stock that was never sold. So please take a close look and if you can use 'em, they're yours! There are 3 included in this listing for the stated price. See my other listings for vintage guitars and parts and various guitar items.