This is a sponge cushion type shoulder rest. The adhesive gel on the back allows you to attach and detach it from the instrument body repeatedly. Thickness: Approximately 12-14mm, Size: Approximately 9cm For 4/4 violin I am selling this because the height doesn't quite fit me. I have only used it about 5 times, so I think the adhesion to the instrument is not a problem. The photos from the 1st to the 3rd are of the actual product, and the photos from the 4th onward are product images from Amazon. The 3rd photo shows the adhesive gel part with the release paper attached to prevent dirt. This is the product: https://amzn.asia/d/0g2wiLY I'm sorry, but I cannot offer a discount.